FIX: Make deleted topic post bookmarks more resilient (PR #10619)

This PR ensures that new bookmarks cannot be created for deleted posts and topics, and also makes sure that if a bookmark was created and then the topic deleted that the show topic page does not error from trying to retrieve the bookmark reminder at.

GitHub

The title of this pull request changed from “FIX: Make deleted topic post bookmarks more resilient and auto delete bookmarks” to "FIX: Make deleted topic post bookmarks more resilient