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

issueで参照されているcreateKubernetesCluster APIと、assignVirtualMachineToBackupOffering APIおよびremoveVirtualMachineFromBackupOffering APIから始めます。CKSのデプロイ中にバックアップオファリングをどのように選択すべきか、またVeleroを対象範囲に含めるかどうかを確認します。完了時には、controlインスタンスとworkerインスタンスが手動で関連付けなくても、要求されたバックアップオファリングを受け取れるようにします。

索引モデルが issue の本文から書いたものです。