Validate configruration as early as possible - backpropgate "rejected dynamic config" error

[ppalucki]

Not everything will be possible without restartin cri-resource-manager (policy change) - but what ever we do early will improve usability and user expirience.

If we decide to depend on cri-resource-manager code - then we can just call nessesary "config validation" before it is passed down to shoot.

Then we can fail early - when reading extensions configmap.configs (based on ControllerDeployment.values0 , even before first shoot is created (with ControllerRegistration.policy=always) report that in ControllerInstallation object condidtion.

The configMap watcher maps that Shoot/Extensions (which may not exists) but can return error.

cri-resmgr binaray can print whole dynamically created configuration ("-print-config") or even print helps ("config-help") as seen here: https://github.com/intel/cri-resource-manager/blob/master/cmd/cri-resmgr/main.go#L50 we should be able to call config.validate() if they make it public and other helper functions (SetConfig(programatically), SetConfigFromFile, Print)

depends on intel/cri-resource-manager#903