Fix: controller: directly acknowledge unrecordable operation results

Regression introduced in 2.0.1-rc1 by 0363985dd

Before that commit, if an operation result arrived when there was no resource
information available, a warning would be logged and the operation would be
directly acknowledged. This could occur, for example, if resource history were
cleaned while an operation was pending on that resource.

After that commit, in that situation, an assertion and error would be logged,
and no acknowledgement would be sent, leading to a transition timeout.

Restore the direct ack. Also improve related log messages.