Required invitation status check in OCM /invite-accepted is missing

[redblom]

When an open invitation is revoked by the inviter and it has not been cleaned-up yet (by the job runner) the invitee can still accept it and it will become an accepted invitation at both sides.
This is because there is no status check in the OCM controller at the invitor side (endpoint /invite-accepted) for this status.
So in the relatively short period of time (less than a minute) the invitation is still present in the db as a withdrawn invitation the event as described can happen.