Threadhash

[kmahar]

uses code from the other PR i have open, so merge that one first (might be conflicts, lmk)

you'll need to do an auto migration

changes:

• frontend/backend for changing the auto-approve setting
• endpoints to click from email signature that turn moderation on/off for a sender+thread pair
• threadhash logic, if auto-approve setting is on:
  • we store a hash of sender|subject along with foreign key to the related group and a boolean indicating whether the owner has specifically opted in to continue moderation for this user
  • when we get a post from a user, we see if threadhash for them exists
    • if it does and moderate=True, post needs moderation (user opted in)
    • if it does and moderate=False, auto-approve post (this is not their first post, and first one was approved)
    • if it doesn't, then post goes through moderation and (if approved) threadhash will be created and stored upon approval
• better logic for emailing mods
  • when we get a new email find the least recently emailed moderator, and if we haven't emailed them in last 24 hrs, send them a notification and update last emailed time
  • todo: should probably have cron job or similar that resends the notification after 24 hrs if the emails haven't been dealt with yet
• if a squad has no moderators, then automatically approve emails received, and send to owner with a link to add mods
• reworked wording/links in email footers

[amyxzhang]

@kmahar conflicts