Add Sylva Unit to backup ETCD of management cluster and workload clusters

Summary

Add a Sylva unit using the existing kube_cronjob Kustomize unit to back up the etcd of the Management Cluster and the Workload Clusters.

This unit will run the etcdctl snapshot command periodically, ensuring that CAPI configurations are consistently backed up.

Details

1. Add Backup-ETCD Unit:

   • Implement a kube_cronjob resource to schedule the etcdctl snapshot command.

2. Configure Monitoring:

   • Set up monitoring to ensure the backup process succeeds and alerts on failures.