(MCO-360) Remove all references to the 'mcollective' agent

Controller messages have been deprecated for an extremely long time.
After deprecating it we stopped processing messages directed at the
'mcollective' agent but we are still connecting to its related queues
and topics.

This commit removes all trace of the 'mcollective' agent and controller
messages.
Yeah, we can open a ticket to remove these expectations post next release.