Add zen_namespace for auto_br scirpt

[qpdpQ]

What this PR does / why we need it:
In br automation test, user might not deploy zenservice in service namespace, we need to add a new flag for zen namespace.
Which issue(s) this PR fixes:
Fixes # https://github.ibm.com/IBMPrivateCloud/roadmap/issues/67503

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[qpdpQ]

Test log:

./deploy-br-resources.sh --zen --zen-ns cs-1 --operator-ns cs1 --services-ns cs1-data
[INFO] Using default storage class rook-cephfs.
[INFO] Creating Zen Backup/Restore resources in namespace cs-1.
deployment.apps/zen5-backup created
persistentvolumeclaim/zen5-backup-pvc created
configmap/zen5-br-configmap created
role.rbac.authorization.k8s.io/zen5-backup-role created
rolebinding.rbac.authorization.k8s.io/zen5-backup-rolebinding created
serviceaccount/zen5-backup-sa created
[✔] Resources to backup Zen deployed in namespace cs-1.
[✔] Backup/Restore resources created in namespace cs-1.