[API] Add endpoints to list KafkaRebalances and patch action annotation

[MikeEdgar]

Add endpoints to list KafkaRebalance resources and patch the action. The action is a write-only property that translates to the strimzi.io/rebalance annotation on the KafkaRebalance CR.

Integration tests will be added before merging.

[MikeEdgar]

@hemahg , I'm not sure having action in attributes for handling updates is a great approach. This may be better represented by PATCHing this information in another meta entry. Either way, it's fairly minor and the majority of how the endpoints look and feel will remain the same.

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
96.3% Coverage on New Code
2.7% Duplication on New Code

See analysis details on SonarCloud