Allow forced backup deletion

Add --force and --confirm to `ark backup delete` to support forced
backup deletion. This forcibly removes the Ark GC finalizer (if it's
present) from a backup and will orphan any resources associated with the
backup, such as backup tarballs in object storage, persistent volume
snapshots, and restores for the backup.

If a backup has a deletion timestamp, display `Deleting` in `ark backup
describe` and `ark backup get`.

Signed-off-by: Andy Goldstein <andy.goldstein@gmail.com>

pkg/cmd/util/output/backup_printer.go

@@ -87,6 +87,9 @@ func printBackup(backup *v1.Backup, w io.Writer, options printers.PrintOptions)
 	if status == "" {
 		status = v1.BackupPhaseNew
 	}
+	if backup.DeletionTimestamp != nil && !backup.DeletionTimestamp.Time.IsZero() {
+		status = "Deleting"
+	}
 
 	if _, err := fmt.Fprintf(w, "%s\t%s\t%s\t%s\t%s", name, status, backup.CreationTimestamp.Time, humanReadableTimeFromNow(expiration), metav1.FormatLabelSelector(backup.Spec.LabelSelector)); err != nil {
 		return err