Redesign service for master discovery

[razvan]

The problems

1. Currently the master role group must be named default. Additional groups within this role that use different ports will not be added to the NodePort service for this role.

2. Also the operator creates one ClusterIP service per role group but it's not clear if this is necessary.

Possible solution

• Add support for multiple master groups as part of the NodePort service and use that instead of the master ClusterIP for the worker configuration.
• Clarify if a ClusterIP service for workers and the history server is necessary and if not remove them.