Put Murano RabbitMQ HAProxy service on Public IP

Unlike OpenStack RabbitMQ, Murano RabbitMQ uses the Public VIP, that has to be
specified explicitly in openstack::ha::haproxy_service parameters.

Make openstack::ha::murano consistent with other OpenStack services: declare
all related HAProxy services in the same file, do not make it a dependency of
HAProxy itself (only main RabbitMQ HAProxy service needs to have before_start =
true).

Change-Id: I0fd7fb1564b322315b88320a331d5a89f0d74c48
Closes-Bug: #1325983
Merge "Put Murano RabbitMQ HAProxy service on Public IP"