Print "Operation initiated" to show success

If the D-Bus times out on a long-running operation, print a message to
indicate success. Actually, what we are saying here is that success is
the best interpretation of what stratis-cli has detected.

Further efforts would require independent checks.

Signed-off-by: mulhern <amulhern@redhat.com>

Author: mulkieran

src/stratis_cli/_actions/_utils.py

@@ -303,5 +303,6 @@ def wrapper(namespace: Namespace):
                 for e in get_errors(err)
             ):  # pragma: no cover
                 raise err
+            print("Operation initiated", file=sys.stderr)
 
     return wrapper