Add a way to delete projects, badges and user_events

[imjuniper]

I'd like to have a way to do this, mostly for cases of testing badges. As for the user events, because of the way they are stored, if a Perforce user gets renamed, there's a "dead" user event just staying there, which could be confusing, but it's mostly a small annoyance to me. I could (and probably will) manually delete it from the database, but it would be easier to have an api endpoint for it.

Thanks a lot for your project btw, it's much easier for me to use than setting up Horde 😅