Liquid Cinder: Add FCD support

[VoigtS]

This PR aims to support FCD checks from Pools to VolumeTypes via the StorageProtocol and the QualityType.
The old way of matching against the volumeBackendName is still available for the current Pools.

The catch on the new approach is that VolumeTypes might a Encryption attribute attachted to them at some point. Those will have the same StorageProtocol and QualityType as the the one without encryption.
This behavior is similar how we treat volumeBackendName already. The collected Pool capacity will just be split into the matching volumeTypes.

I tested the implementation against the cluster and yes, we do retrieve non-matching Pools into the resultset now.
Please have a look at this, there might be optimization that I can do. Other than that I will update the documentation for the new matching tomorrow.

Checklist:

• If this PR is about a plugin, I tested the plugin against an OpenStack cluster.
  TODO:
• I updated the documentation to describe the semantical or interface changes I introduced.

[coveralls]

coverage: 79.255%. remained the same
when pulling 43d4ae0 on cinder_update
into 0757907 on master.

[majewsky]

Nice, thanks!