Store "resigned" as an explicit reviewer state
Fixes T11050. Today, when a user resigns, we just delete the record of them ever being a reviewer.
However, this means you have no way to say "I don't care about this and don't want to see it on my dashboard" if you are a member of any project or package reviewers.
Instead, store "resigned" as a distinct state from "not a reviewer", and treat it a little differently in the UI:
- On the bucketing screen, discard revisions any responsible user has resigned from.
- On the main /Dxxx page, show these users as resigned explicitly (we could just hide them, too, but I think this is good to start with).
- In the query, don't treat a "resigned" state as a real "reviewer" (this change happened earlier, in D17517).
- When resigning, write a "resigned" state instead of deleting the row.
- When editing a list of reviewers, I'm still treating this reviewer as a reviewer and not special casing it. I think that's sufficiently clear but we could tailor this behavior later.
- Resigned from a revision.
- Saw "Resigned" in reviewers list.
- Saw revision disappear from my dashboard.
- Edited revision, saw user still appear as an editable reviewer. Saved revision, saw no weird side effects.
Reviewed By: chad
Maniphest Tasks: T11050
Differential Revision: https://secure.phabricator.com/D17531