Add rmq cluster to 'rabbitmq' category

[ChunyiLyu]

This closes #

Note to reviewers: remember to look at the commits in this PR and consider if they can be squashed

Summary Of Changes

For convenience, this adds rabbitmqclusters crd to category rabbitmq (PR that does the same to all topology CRDs: rabbitmq/messaging-topology-operator#327).

So When you do kubectl get rabbitmq, you see:

❯ k get rabbitmq
NAME                            AGE
queue.rabbitmq.com/qq-example   8m26s

NAME                                  ALLREPLICASREADY   RECONCILESUCCESS   AGE
rabbitmqcluster.rabbitmq.com/sample   True               True               13m

NAME                            AGE
user.rabbitmq.com/user-sample   5m10s

... and all other rabbitmq resouces

Additional Context

Local Testing

Please ensure you run the unit, integration and system tests before approving the PR.

To run the unit and integration tests:

$ make unit-tests integration-tests

You will need to target a k8s cluster and have the operator deployed for running the system tests.

For example, for a Kubernetes context named dev-bunny:

$ kubectx dev-bunny
$ make destroy deploy-dev
# wait for operator to be deployed
$ make system-tests