Granular Reporter Permissions

This adds an architecture for liveupdate reporters having granular permissions. Initially, I've carved up the current actions into some sane-seeming groups.

One major difference here from mod permissions that I'm not sure of is the existence of the "manage reporters" permission.  The equivalent permission for mods is only available to "superuser" (all permission) mods.  I felt like it'd be better to be explicit about permissions, but it is a bit inconsistent.

I think I can roll this out without blocking on any sort of age supremacy like moderator permissions have.  That may end up being necessary, but I think this is sufficient for now. Perhaps there's an alternate, superior, way of handling that kind of dispute anyway?

Like with the [editor -> reporter rename](da9d11882fec76290226cb6270f49bf820d3ae88), I'll manually update existing events to give full permissions to all extant reporters.

:eyeglasses: @chromakode @andre-d (because of the userlisting stuff)