FEATURE: Show stale reviewable to other clients (PR #13114)

We did not update other clients allowing multiple users to take action on a resolved reviewable. This commit will continue removing the reviewable for the acting user and the other users will see a greyed out reviewable, an updated status (i.e. Pending → Rejected) and a message at the bottom (instead of actions).

GitHub

Test failures are legit

so cool! thanks Dan