No need to let notifications stay around when users can't access
a topic after it was converted into a PM or posts were moved
into a restricted topic.
Also makes sure that moving to a new topic correctly uses the
guardian for the first post by enqueuing jobs outside of a
transaction.
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
Includes support for flags, reviewable users and queued posts, with REST API
backwards compatibility.
Co-Authored-By: romanrizzi <romanalejandro@gmail.com>
Co-Authored-By: jjaffeux <j.jaffeux@gmail.com>
