This PR introduces Auth Server CRUD API for managing the lifecycle of dynamic `kube_cluster` resources.
Currently, `kube_cluster` resources cannot be manipulated without using the API, nor are they being listened to. It will be part of future developments.
# Future work
- The `kubernetes_service` will have to watch these `kube_cluster` resources.
- The discovery service will have to create these resources.
Resource manipulation via `tctl` will be introduced later and is not part of the scope.
Part of #16135, #13376
Related to #12048