Add a function to upgrade from full HA to NG HA

Add a function to upgrade from full HA to NG HA

This is the initial work to have a function that migrates a full HA
architecture as deployed in Mitaka to the HA architecture as deployed in
Newton where only a few resources are managed by pacemaker.

The sequence is the following:
1) We remove the desired services from pacemaker's control. The services
   at this point are still running normally via the systemd service as
   invoked by pacemaker
2) We do a "systemctl stop <service>" on all controllers for all the
   services that were removed from pacemaker's control. We do this to make
   sure that during the yum upgrade, the %post sections that call
   "systemctl try-restart" do not take ages, because at this point during
   the upgrade rabbit is down. The only exceptions are "openstack-core"
   and "delay" which are dummy pacemaker resources that do not exist on
   the system
3) We do a "systemctl start <service>" on all nodes for all the services
   mentioned above.

We should probably merge this patch only when newton has branched as it
is very specific to the M/N upgrade.

Closes-Bug: 1617520
Change-Id: I4c409ce58c1a57b6e0decc3cf168b62698b32e39