Fix MariaDB operator deployment namespace issue

- Remove namespace from kustomization.yaml (was putting Apps in wrong namespace)
  - Change destination to argocd namespace (Application resources must be there)
  - Add labels for tracking parent app

apps/templates/mariadb-operator-folder.yaml

@@ -13,7 +13,7 @@ spec:
     path: mariadb-operator
   destination:
     server: https://kubernetes.default.svc
-    namespace: mariadb-system
+    namespace: argocd
   syncPolicy:
     syncOptions:
     - CreateNamespace=true