Is your feature request related to a problem? Please describe.
I want to define user limit max-connections as described in: https://www.rabbitmq.com/docs/user-limits#connections

Describe the solution you'd like
I would like to use the messaging-topology-operator for defining user max-connections limits.

Describe alternatives you've considered
We could use custom scripts to achieve this, but it would be so nice to have this converted in this operator.

Additional context
It would be best to have additional resource like Limits with the possibility to set max-connections / max-queues for a specific user / vhost. Basically what is supported on Admin -> Limits page on webui.