test: remove withSolanaAccountSnap as we have default Multichain support in all our e2e (#40327)

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## **Description**
This PR removes the `withSolanaAccountSnap` method, as we have default
Multichain support in all our e2e, so we don't need the duplicated setup
of feature flags etc (which is already set by default).
All specs start the wallet with multichain accounts, meaning this method
is now obsolete/missleading/duplicated.

Instead of `withSolanaAccountSnap` we can use `withFixtures` out of the
box.

This simplifies test setup and makes the tests also easier to debug and
maintain.
Additional changes:
- whenever it was possible, used FixtureBuilderV2 instead of the legacy
one (see data below)
- removed dead code

Note: e2e quality gate is disabled due to the number of specs changed,
causing the ci to timeout due to extra test runs.

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## **Changelog**

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`CHANGELOG entry: Added a new tab for users to see their NFTs`
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CHANGELOG entry:

## **Related issues**

Fixes:

## **Manual testing steps**

1. All ci tests should continue to pass

## **Screenshots/Recordings**

<!-- If applicable, add screenshots and/or recordings to visualize the
before and after of your change. -->

### **Before**
This data is for the migration of V2 fixtures (before and after): 

<img width="3059" height="1541" alt="image"
src="https://github.com/user-attachments/assets/19a37600-8c86-4e74-80ef-3dd63f679b22"
/>


### **After**

<img width="3059" height="1541" alt="image"
src="https://github.com/user-attachments/assets/6f697891-9aef-49c9-805a-59c2862019c6"
/>


## **Pre-merge author checklist**

- [ ] I've followed [MetaMask Contributor
Docs](https://github.com/MetaMask/contributor-docs) and [MetaMask
Extension Coding
Standards](https://github.com/MetaMask/metamask-extension/blob/main/.github/guidelines/CODING_GUIDELINES.md).
- [ ] I've completed the PR template to the best of my ability
- [ ] I’ve included tests if applicable
- [ ] I’ve documented my code using [JSDoc](https://jsdoc.app/) format
if applicable
- [ ] I’ve applied the right labels on the PR (see [labeling
guidelines](https://github.com/MetaMask/metamask-extension/blob/main/.github/guidelines/LABELING_GUIDELINES.md)).
Not required for external contributors.

## **Pre-merge reviewer checklist**

- [ ] I've manually tested the PR (e.g. pull and build branch, run the
app, test code being changed).
- [ ] I confirm that this PR addresses all acceptance criteria described
in the ticket it closes and includes the necessary testing evidence such
as recordings and or screenshots.



<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Medium Risk**
> Broad test-harness refactor touching many E2E specs and mocks; risk is
primarily increased CI flakiness or missing setup
(login/network/account) causing false failures rather than production
impact.
> 
> **Overview**
> Removes the bespoke Solana E2E harness `withSolanaAccountSnap` in
favor of using `withFixtures` directly across Solana/multichain specs,
updating tests to explicitly log in, switch to Solana where needed, and
pass `fixtures`/`dappOptions`/`testSpecificMock` per scenario.
> 
> Refactors Solana test mocking by introducing
`buildSolanaTestSpecificMock` (and `SolanaMockOptions`) plus a more
flexible `mockSolanaBalanceQuote` signature, and updates affected
swap/SPL/tx tests accordingly. Adds a reusable `addAccount` flow for
creating/switching multichain accounts, extends `FixtureBuilderV2` with
`withShowNativeTokenAsMainBalanceDisabled`, and tweaks
`HomePage.checkPageIsLoaded` to wait on the balance section rather than
the send button.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
891c68a. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: seaona

test/e2e/fixtures/fixture-builder-v2.ts

@@ -160,6 +160,14 @@ class FixtureBuilderV2 {
     });
   }
 
+  withShowNativeTokenAsMainBalanceDisabled(): this {
+    return this.withPreferencesController({
+      preferences: {
+        showNativeTokenAsMainBalance: false,
+      },
+    });
+  }
+
   build() {
     return this.fixture;
   }

test/e2e/flask/multichain-api/non-evm/wallet_createSession.spec.ts

@@ -1,23 +1,27 @@
 import { strict as assert } from 'assert';
 import { By } from 'selenium-webdriver';
-import { largeDelayMs } from '../../../helpers';
+import { largeDelayMs, withFixtures } from '../../../helpers';
+import { SOLANA_MAINNET_SCOPE } from '../../../constants';
+import FixtureBuilderV2 from '../../../fixtures/fixture-builder-v2';
+import { loginWithBalanceValidation } from '../../../page-objects/flows/login.flow';
+import { addAccount } from '../../../page-objects/flows/add-account.flow';
 import TestDappMultichain from '../../../page-objects/pages/test-dapp-multichain';
 import { DEFAULT_MULTICHAIN_TEST_DAPP_FIXTURE_OPTIONS } from '../testHelpers';
-import { withSolanaAccountSnap } from '../../../tests/solana/common-solana';
 
 describe('Multichain API - Non EVM', function () {
-  const SOLANA_SCOPE = 'solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp';
   describe("Call `wallet_createSession` with both EVM and Solana scopes that match the user's enabled networks", function () {
     it('should only select the specified scopes requested by the user', async function () {
-      await withSolanaAccountSnap(
+      await withFixtures(
         {
           ...DEFAULT_MULTICHAIN_TEST_DAPP_FIXTURE_OPTIONS,
+          fixtures: new FixtureBuilderV2().build(),
           title: this.test?.fullTitle(),
         },
-        async (driver, _, extensionId) => {
+        async ({ driver, extensionId }) => {
+          await loginWithBalanceValidation(driver);
           const requestScopesToNetworkMap = {
             'eip155:1': 'Ethereum',
-            [SOLANA_SCOPE]: 'Solana',
+            [SOLANA_MAINNET_SCOPE]: 'Solana',
           };
 
           const requestScopes = Object.keys(requestScopesToNetworkMap);
@@ -72,17 +76,20 @@ describe('Multichain API - Non EVM', function () {
 
   describe('Connect wallet to the multichain dapp via `externally_connectable`, call `wallet_createSession` with Solana scope, without any accounts requested', function () {
     it('should automatically select the current active Solana account', async function () {
-      await withSolanaAccountSnap(
+      await withFixtures(
         {
           ...DEFAULT_MULTICHAIN_TEST_DAPP_FIXTURE_OPTIONS,
+          fixtures: new FixtureBuilderV2().build(),
           title: this.test?.fullTitle(),
-          numberOfAccounts: 2,
         },
-        async (driver, _, extensionId) => {
+        async ({ driver, extensionId }) => {
+          await loginWithBalanceValidation(driver);
+          await addAccount({ driver, switchToAccount: 'Account 1' });
+
           const testDapp = new TestDappMultichain(driver);
           await testDapp.openTestDappPage();
           await testDapp.connectExternallyConnectable(extensionId);
-          await testDapp.initCreateSessionScopes([SOLANA_SCOPE]);
+          await testDapp.initCreateSessionScopes([SOLANA_MAINNET_SCOPE]);
 
           const editButtons = await driver.findElements('[data-testid="edit"]');
           await editButtons[0].click();

test/e2e/flask/multichain-api/non-evm/wallet_invokeMethod.spec.ts

@@ -1,27 +1,31 @@
 import { strict as assert } from 'assert';
 import { isObject } from 'lodash';
-import { WINDOW_TITLES } from '../../../constants';
+import { SOLANA_MAINNET_SCOPE, WINDOW_TITLES } from '../../../constants';
 import TestDappMultichain from '../../../page-objects/pages/test-dapp-multichain';
 import { DEFAULT_MULTICHAIN_TEST_DAPP_FIXTURE_OPTIONS } from '../testHelpers';
-import { withSolanaAccountSnap } from '../../../tests/solana/common-solana';
+import { buildSolanaTestSpecificMock } from '../../../tests/solana/common-solana';
+import { withFixtures } from '../../../helpers';
+import FixtureBuilderV2 from '../../../fixtures/fixture-builder-v2';
+import { loginWithBalanceValidation } from '../../../page-objects/flows/login.flow';
 import SnapTransactionConfirmation from '../../../page-objects/pages/confirmations/snap-transaction-confirmation';
 import SnapSignInConfirmation from '../../../page-objects/pages/confirmations/snap-sign-in-confirmation';
 
 describe('Multichain API - Non EVM', function () {
-  const SOLANA_SCOPE = 'solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp';
   describe('Calling `wallet_invokeMethod`', function () {
     describe('signIn method', function () {
       it('Should match selected method to the expected confirmation UI', async function () {
-        await withSolanaAccountSnap(
+        await withFixtures(
           {
             ...DEFAULT_MULTICHAIN_TEST_DAPP_FIXTURE_OPTIONS,
+            fixtures: new FixtureBuilderV2().build(),
             title: this.test?.fullTitle(),
           },
-          async (driver, _, extensionId) => {
+          async ({ driver, extensionId }) => {
+            await loginWithBalanceValidation(driver);
             const testDapp = new TestDappMultichain(driver);
             await testDapp.openTestDappPage();
             await testDapp.connectExternallyConnectable(extensionId);
-            await testDapp.initCreateSessionScopes([SOLANA_SCOPE]);
+            await testDapp.initCreateSessionScopes([SOLANA_MAINNET_SCOPE]);
             await driver.clickElementAndWaitForWindowToClose({
               text: 'Connect',
               tag: 'button',
@@ -32,7 +36,7 @@ describe('Multichain API - Non EVM', function () {
             );
 
             await testDapp.invokeMethod({
-              scope: SOLANA_SCOPE,
+              scope: SOLANA_MAINNET_SCOPE,
               method: 'signIn',
             });
 
@@ -47,17 +51,21 @@ describe('Multichain API - Non EVM', function () {
 
     describe('signAndSendTransaction method', function () {
       it('Should match selected method to the expected confirmation UI', async function () {
-        await withSolanaAccountSnap(
+        await withFixtures(
           {
             ...DEFAULT_MULTICHAIN_TEST_DAPP_FIXTURE_OPTIONS,
+            fixtures: new FixtureBuilderV2().build(),
             title: this.test?.fullTitle(),
-            mockGetTransactionSuccess: true,
+            testSpecificMock: buildSolanaTestSpecificMock({
+              mockGetTransactionSuccess: true,
+            }),
           },
-          async (driver, _, extensionId) => {
+          async ({ driver, extensionId }) => {
+            await loginWithBalanceValidation(driver);
             const testDapp = new TestDappMultichain(driver);
             await testDapp.openTestDappPage();
             await testDapp.connectExternallyConnectable(extensionId);
-            await testDapp.initCreateSessionScopes([SOLANA_SCOPE]);
+            await testDapp.initCreateSessionScopes([SOLANA_MAINNET_SCOPE]);
             await driver.clickElementAndWaitForWindowToClose({
               text: 'Connect',
               tag: 'button',
@@ -70,7 +78,7 @@ describe('Multichain API - Non EVM', function () {
             const invokeMethod = 'signAndSendTransaction';
 
             await testDapp.invokeMethod({
-              scope: SOLANA_SCOPE,
+              scope: SOLANA_MAINNET_SCOPE,
               method: invokeMethod,
             });
 
@@ -86,7 +94,7 @@ describe('Multichain API - Non EVM', function () {
             );
 
             const transactionResult = await testDapp.getInvokeMethodResult({
-              scope: SOLANA_SCOPE,
+              scope: SOLANA_MAINNET_SCOPE,
               method: invokeMethod,
             });
             const parsedTransactionResult = JSON.parse(transactionResult);

test/e2e/flask/snaps/test-snap-protocol.spec.ts

@@ -1,19 +1,26 @@
 import { openTestSnapClickButtonAndInstall } from '../../page-objects/flows/install-test-snap.flow';
 import { DEFAULT_MULTICHAIN_TEST_DAPP_FIXTURE_OPTIONS } from '../multichain-api/testHelpers';
 import { DAPP_ONE_URL, WINDOW_TITLES } from '../../constants';
-import { withSolanaAccountSnap } from '../../tests/solana/common-solana';
+import { buildSolanaTestSpecificMock } from '../../tests/solana/common-solana';
+import { withFixtures } from '../../helpers';
+import FixtureBuilder from '../../fixtures/fixture-builder';
+import { loginWithBalanceValidation } from '../../page-objects/flows/login.flow';
 import ConnectAccountConfirmation from '../../page-objects/pages/confirmations/connect-account-confirmation';
 import TestDappMultichain from '../../page-objects/pages/test-dapp-multichain';
 
 describe('Test Protocol Snaps', function () {
   it('can call getBlockHeight exposed by Snap', async function () {
-    await withSolanaAccountSnap(
+    await withFixtures(
       {
+        fixtures: new FixtureBuilder().build(),
         title: this.test?.fullTitle(),
-        withProtocolSnap: true,
         ...DEFAULT_MULTICHAIN_TEST_DAPP_FIXTURE_OPTIONS,
+        testSpecificMock: buildSolanaTestSpecificMock({
+          withProtocolSnap: true,
+        }),
       },
-      async (driver, mockServer, extensionId) => {
+      async ({ driver, mockServer, extensionId }) => {
+        await loginWithBalanceValidation(driver);
         const mockBlockHeight = 368556246;
         await mockServer
           .forPost('https://api.devnet.solana.com/')