Set the new AZ name in rack properties

[mflendrich]

Issue originally authored by tnozicka as #1225

Is this a bug report or feature request?

• Feature Request

What should the feature do:
In order for ScyllaDB to fill in AZ names in peers table it needs to learn what AZ is this node in. The operator will set the AZ in rack rack_properties config file when creating a ScyllaCluster.

What is use case behind this feature:
Supporting new drivers.

Additional Information:
Requires:

• RFE: Expose availability zone name in peers table scylladb#13602