After having the "manual" mechanism of rebalancing on scale up and down with ENTMQST-3976 in place, we would need a way for having the cluster operator doing the operation in an automatic way instead of being user driven.

The proposal should be about flashing out how the automation should work (i.e. auto creation of the KafkaRebalance custom resource) and what's the control that user have (i.e. some way to define when the rebalancing should happen automatically or not).