fix(firebase_ui_auth): actionsBeforeDelete callback

[khanliKU]

Description

Add actionsBeforeDelete callback to ProfileScreen and DeleteAccountButton

Related Issues

N/A

Checklist

Before you create this PR confirm that it meets all requirements listed below by checking the relevant checkboxes ([x]). This will ensure a smooth and quick review process. Updating the pubspec.yaml and changelogs is not required.

• [x] I read the Contributor Guide and followed the process outlined there for submitting PRs.
• [x] My PR includes unit or integration tests for all changed/updated/fixed behaviors (See Contributor Guide).
• [x] All existing and new tests are passing.
• [x] I updated/added relevant documentation (doc comments with ///).
• [x] The analyzer (melos run analyze) does not report any problems on my PR.
• [x] All unit tests pass (melos run test:unit:all doesn't fail).
• [x] I read and followed the Flutter Style Guide.
• [x] I signed the CLA.
• [x] I am willing to follow-up on review comments in a timely manner.

Breaking Change

Does your PR require plugin users to manually update their apps to accommodate your change?

• [ ] Yes, this is a breaking change.
• [x] No, this is not a breaking change.

[khanliKU]

I wanted to provide some additional context: In my application, I needed to perform some cleanup work after the user accepted the "delete user" dialog. I wanted to ensure that all user records were cleared in the Firestore database, so I added an actionBeforeDelete callback. I wanted to share it with the community.

[khanliKU]

I am waiting for this to be merged.