Support Backup offerings for CKS Cluster deployment

### The required feature described as a wish

As a User/Admin/Operator I would like to ,associated a backup offering to be associated with a cks cluster .

Currently, there is no way to associate a Backup offering during CKS deployment

https://cloudstack.apache.org/api/apidocs-4.22/apis/createKubernetesCluster.html

Associating a backup offering is only possible when virtual machine is deployed from the ui api

https://cloudstack.apache.org/api/apidocs-4.22/apis/assignVirtualMachineToBackupOffering.html
https://cloudstack.apache.org/api/apidocs-4.22/apis/removeVirtualMachineFromBackupOffering.html

Currently user has to manually associate cks-instance (control and worker node ) to a backup offering

Also, we can take a look to support velero as a backup provider for kubernetes cluster

https://velero.io/

Currently hyperscalers support kubernetes backup offering

https://docs.aws.amazon.com/eks/latest/userguide/integration-backup.html
https://learn.microsoft.com/en-us/azure/backup/azure-kubernetes-service-backup-overview
https://docs.cloud.google.com/kubernetes-engine/docs/add-on/backup-for-gke/concepts/backup-for-gke

Beginne mit der in der Issue referenzierten API createKubernetesCluster sowie den APIs assignVirtualMachineToBackupOffering und removeVirtualMachineFromBackupOffering. Ermittle, wie während der CKS-Bereitstellung ein Backup Offering ausgewählt werden sollte und ob Velero im Umfang enthalten ist; nach Abschluss sollten Control- und Worker-Instanzen das angeforderte Backup Offering ohne manuelle Zuordnung erhalten können.

Vom Indexierungsmodell aus dem Issue-Text verfasst.