[APIView UI] Update "Approve" button to more Github-like UX

Right now we have a two state button for "Approve" and "Revoke Approval" We want to extend this to be more like Github.

The button should be "Submit Review". This triggers a pop-up:
- Comment field to customize the email (optional)
- "Feedback" option means, not approved--see comments inline.
- "Approve" does exactly what you expect.

Regardless, once submitted, this will trigger the email to the service team that will include all comments made since the last submitted review.

The service team will then see the button either as "Approved" (if it was approved) or "Re-request Review" if it was in feedback. This will send an email to the Reviewers that the API is ready for re-review.

Start in the APIView UI by tracing the existing “Approve” and “Revoke Approval” flow, including how review comments and emails are submitted. Compare the current service-team and reviewer states with the requested “Submit Review,” “Feedback,” “Approve,” and “Re-request Review” states. Done means the popup, submission behavior, email contents, and post-submission labels match the issue description.

Written by the indexing model from the issue text.