mgr/orchestrator: Remove `(add|test|remove)_stateful_service_rule`
No orchestrator implements this interface
The distinction between DriveGroups end stateful_service_rule is not clear
Has not been discussed in #21046 nor jcsp#6 nor #23412
It is not documented.
This is supposed to be some form of persistent drive group. I'm not sure, if we should aim for this at this point.
Signed-off-by: Sebastian Wagner firstname.lastname@example.org