Fixes #6544 - q to receive candlepin events

This creates a queue so that katello can receive candlepin events.
It also sets config items for the queue's url and address in katello.yml so katello can
connect to the queue.
Unless you plan to allow users to customize this value there is no need to put it here in the params file and instead you can put it directly into the qpid.pp class as a variable.