[Sprint/PinkPanther](fix): Delete activity after moderation queue rejection #504
Closes #504 (moved)
Summary
On production right now, if you reject a post in a group you moderate, the post no longer appears in the queue, but still shows up in the feed for mods only like so:
Testing
- Make a group, make it moderated.
- Login to a secondary account, create posts numbered 1, 2, 3, 4, 5.
- Log-in to primary account, look at the group, see the posts with "awaiting moderation"
- Go to the moderation queue and reject the post numbered 3.
- Check that the activity with the content '3' is not visible on the feed with its "awaiting moderation"