Support S3 backends for glance. Since the revival of the S3 glance store driver upstream we have more and more customers who want to storage images on external object stores which are exposing S3 API.

The goal of this epic is to fully support Glance S3 as a core openstack feature but also implement any changes required in the glance operator to deploy/configure it.

Core feature is already available in RHOSO we need test + deployment method.