R1:97cac83e9b0c

Add a "Needs Verification" state to Audit

Summary:
Fixes T2393. This allows authors to explicitly say "I think I fixed everything, please accept my commit now thank you".

Also improves behavior of "re-accept" and "re-reject" after new auditors you have authority over get added.

Test Plan:
- Kicked a commit back and forth between an author and auditor by alternately using "Request Verification" and "Raise Concern".
- Verified it showed up properly in bucketing for both users.
- Accepted, added a…