New home for rabbitmq-server-ha RA OCF m/s HA

Moving it from repo:
https://github.com/rabbitmq/rabbitmq-server
The original path:
scripts/rabbitmq-server-ha.ocf

Reasoning behind: the OCF RA script provides M/S HA
resource for RabbitMQ cluster.

Background
==========
It's been actively maintained for years.
And now it needs a new home due to requests of RabbitMQ team,
since it is no longer possible to run CI tests for changes
proposed against it by the old location.

TripleO upstream project and its layered RH OSP product have plans
to adopt this OCF RA for its use. That guarantees the future
maintanance and support for it.

Future Plans
============
Once it is there, the package builds for RDO will catch up
changes for that OCF RA and make sure it's CI'ed, also in TripleO
and OSP.

Status Quo
==========
Until the adoption completes, I'm planning to test changes proposed
by this new location in my fork, with github actions, like [0].
The CI runs on pre-build images [1] and vagrant scripts [1] that
I maintain for the (more or less) recent Pacemaker and RabbitMQ
builds. The test coverage includes a simple cluster assemble smoke
test and a sofisticated Jepsen testcase that verifies auto-healing
of the cluster resource in Pacemaker managed by this OCF RA.

[0] https://github.com/bogdando/rabbitmq-server/runs/3757495446
[1] https://hub.docker.com/r/bogdando/rabbitmq-cluster-ocf
[2] https://github.com/bogdando/rabbitmq-cluster-ocf-vagrant

Signed-off-by: Bogdan Dobrelya <bdobreli@redhat.com>