Fixes #5628 - remove converted v1 API controllers and tests.

Remove all of the v1 controllers and tests that have already been converted to v2 and are no longer used.

http://projects.theforeman.org/issues/5628
https://bugzilla.redhat.com/show_bug.cgi?id=1112836
If there's nothing in the UI or CLI that uses it, i don't think we should go and add a v2 controller action just because.  However it seems like we should open an issue allowing a user to list package groups from the cli (and possibly the UI?).