* Add ability to mark moderation reports as 'handled' or 'rejected'.
* Automatically mark reports as handled when the comment or forum post
is deleted.
* Send a dmail to the reporter when their report is handled.
* Don't show the report notice on comments or forum posts when all
reports against it have been handled or rejected.
* Add a fix script to mark all existing reports for deleted comments,
forum posts, or dmails as handled.
* Add data-is-deleted, data-updater-id, data-topic-id, and
data-topic-is-deleted data attributes to forum posts.
* Change data-forum-post-id to data-id.
* Dim deleted forum posts like comments.
This refactors Pundit policies to only rely on the current user, not on
the current user and the current HTTP request. In retrospect, it was a
bad idea to include the current request in the Pundit context. It bleeds
out everywhere and there are many contexts (in tests and models) where
we only have the current user, not the current request. The previous
commit got rid of the only two places where we used it.
