Managed control planes

[Unix4ever]

### Tasks
- [ ] create a controller for handling machine request set which is created for managed control planes
- [ ] https://github.com/siderolabs/omni/issues/550
- [ ] block Talos API access to the managed control planes
- [ ] -- POC
- [ ] https://github.com/siderolabs/omni/issues/551
- [ ] https://github.com/siderolabs/omni/issues/594
- [ ] https://github.com/siderolabs/omni/issues/595
- [ ] support the mode when the control plane node doesn't register itself in the kubelet
- [ ] disable downgrades for the clusters with managed control plane
- [ ] have more strict list of usable Talos versions for the clusters with managed control planes