Load rabbitmq plugins from OCF script

Rabbitmq plugins do not work in HA mode since we start rabbitmq
server with RABBITMQ_NODE_ONLY=1 which disables plugins.
So we just load them with a piece of Erlang code sent to rabbitmq
via "rabbitmqctl eval".

Change-Id: Ib7e7d02bbf5f7185646c0fefbc4317d9bf5c4566
Closes-bug: #1354026
Merge "Load rabbitmq plugins from OCF script"