Implement Object Storage Operator

As an SCS-IaaS operator, I want to quickly & easily install all required components. So far, there is no drop-in solution to supply the S3 object storage service mandated by SCS-0123.

This Operator must offer the following features to be a MVP:

• a Keystone-authenticated S3 service is available from the OpenStack catalog
• supported backend: Ceph

This is also in preparation for an SCS Operator (which will check that S3 is available) and to familiarize us with developing Yaook Operators.

Since it is likely that a Swift compatible service (via Ceph) will get incorporated into this Operator as well, I'm going with a protocol-agnostic name for now.

If the Yaook maintainers are hesitant to bring this upstream, a stand-alone implementation is acceptable. In that case, images and charts won't be available from any registry, requiring users to build them themselves.