New config strategy to adapt to oslo-messaging

* Extract and remove --config-file amqp_openstack.conf(or
  amqp-openstack-neutron and --config-file amqp-powervc.conf from sys.argv to
  create 2 AMQP cfg.ConfigOpts objects without conflicting with other options
  parsing as before, particularly those OpenStack AMQP configurations in
  [DEFAULT] section of nova.conf, cinder.conf.

* adapt all affected code to the new config strategy

Implements: blueprint
https://blueprints.launchpad.net/powervc-driver/+spec/new-configuration-strategy-needed-to-adapt-to-oslo-messaging

Closes-Bug: 1356225
Change-Id: I61a4fd0c28148e31a8cb85acea3793f40028dfb4