Added ErrorMessage schema

[Steveb-p]

🎫 Issue	IBX-XXXXX

Description:

This PR adds ErrorMessage (internal://ibexa/rest/ErrorMessage) as schema usable for tests.

It also changes how Response validation is done, allowing expected HTTP code and expected schema to be customized.

For QA:

Documentation:

[Copilot]

Pull Request Overview

This PR adds ErrorMessage schema support for REST API testing and refactors response validation to allow customization of expected HTTP codes and schemas. The changes improve test flexibility by enabling custom schema locations and removing redundant type assertions.

Key changes:

• Added ErrorSchemaProvider for ibexa/rest/ErrorMessage schema validation
• Refactored response validation to accept EndpointRequestDefinition instead of separate parameters
• Added schemaLocation property to EndpointRequestDefinition for custom schema paths

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/lib/Schema/ErrorSchemaProvider.php	Implements schema provider for ErrorMessage with required properties
src/contracts/Request/Value/EndpointRequestDefinition.php	Adds schemaLocation property and getter/setter methods
src/contracts/BaseRestWebTestCase.php	Refactors validation methods to use EndpointRequestDefinition parameter
src/bundle/Resources/config/services/rest_schema.yaml	Registers ErrorSchemaProvider as tagged service
phpstan-baseline.neon	Removes baseline entry for redundant string type assertion

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[Copilot]

Consider using an array instead of casting to object with (object). The schema structure is already defined as an associative array, and the object cast adds unnecessary complexity without clear benefit.

Suggested change

	yield 'ibexa/rest/ErrorMessage' => (object)[
	yield 'ibexa/rest/ErrorMessage' => [

[Copilot]

The refactoring from manual status code assertion to assertResponseStatusCodeSame() is good, but the custom error message providing context about expected vs actual status codes has been lost. Consider preserving the descriptive error message for better test failure diagnostics.

Suggested change

	self::assertResponseStatusCodeSame($expectedStatusCode);
	self::assertResponseStatusCodeSame(
	$expectedStatusCode,
	sprintf(
	'Expected status code %d but got %d for endpoint [%s %s]',
	$expectedStatusCode,
	$this->client?->getResponse()?->getStatusCode(),
	$endpointDefinition->getMethod(),
	$endpointDefinition->getUri()
	)
	);