[Sprint/NuancedNumbat](fix): Ban email now returning string of ban reason rather than index.

Closes #867 (closed)

Depends on helm-charts!41 (merged)

Summary

Change integers returned into their human readable banned reason.

Steps to test

Emails ARE working on sandboxes now, but the Email runner still isn't, this means directly dispatched emails send instantly (like the 3 strikes email), queued ones do not (like the one we're changing).

tl;dr Will require kubectl access

1. kubectl exec into the container.
2. cd engine.
3. php ./cli.php QueueRunner run --runner=Email.
4. Now log in as sandbox admin and ban a user for spam.
5. Reason should come through in the email.

Regression Scope

This is mostly additions so I wouldn't expect there's much room for anything to go wrong outside of the new additions being faulty in some way. I suppose as a ground zero, worst case scenario; ban email maybe doesn't send because of an uncaught error, but this isn't likely or the case when testing.