AcknowledgeUndeliveredNotices

Take responsibility for the holders of a scheduled change who could not be told (AllocationManage, AND the caller must be the one who requested the change or a fund owner). A change that TIGHTENS the terms does not bind while a holder's notice is undelivered; for a holder the identity plane can never reach that is forever. This records who acknowledged, when, and exactly which holders' notices the mailer had GIVEN UP on by that moment (notices_given_up, never a notice still being tried), and the change then binds over those holders — and over nobody else who turns out untold later. A later call ADDS the holders given up on since (notices_unacknowledged) and stands as the latest: its caller and moment replace the record's, taking responsibility for the whole list. A repeat that would add nobody returns the record unchanged. ALREADY_EXISTS when the change is not scheduled, only loosens the terms (it binds by itself), or has no notice given up on yet that is not already covered — there is nothing to take responsibility for; PERMISSION_DENIED for a caller who is neither the requester nor an owner.