Adds popup notif. (fixes #1183)

[victorialee13]

Summary

Improves the sign-out flow by showing a notification when the user signs out of their Google Account.
This update uses the global openSnackbar action to display a top-right toast message including the user's name or email (when available).
The logout notification appears before the session is cleared to ensure it is always visible to the user.

Test Plan

Manually signed it with test account and clicked 'Sign out'.
Dropdown menu closes and Snackbar appear top right corner
Message shows one of three choices

1. account name
2. account email
3. 'your account' as fallback
   After 800ms delay, session clears through clearSession() and redirects to /.

Issues

Closes #1183

[alexespejo]

Congrats on your first PR!!

This looks like a solid start! This is a smaller change so it's not too big but in the future if you can provide screen shots in the PR that would be good 🙂

When it comes to user signin notifications we typically use dialogs or popups like this to inform them:

We create an AlertDialog component for this particular instance

[victorialee13]

Summary
Changes Snackbar Notification which notifies users they have been signed out to instead using the AlertDialong Component

Test Plan
Manually signed it with test account and clicked 'Sign out'.

Closes #1183

[alexespejo]

My fault, I gave bad instructions that are too overkill.

Revert the commits related to the suggested change.

The flow should be:

"Hit logout" -> invalidates session -> display alert -> "user hits close" -> reload the page

*the current issue is if you hit logout the user HAS to hit "close" in order to be properly invalidated without being dependent on the user input

[alexespejo]

Resolve the merge conflicts so the deployment can run

[alexespejo]

Looks good for the most part. Remove the small changes and you're good to go!

[alexespejo]

LGTM

[brelieu05]

lgtm