[9.18] Don't process detach and close as priority netmgr events
The detach (and possibly close) netmgr events can cause additional callbacks to be called when under exclusive mode. The detach can trigger next queued TCP query to be processed and close will call configured close callback.
Move the detach and close netmgr events from the priority queue to the normal queue as the detaching and closing the sockets can wait for the exclusive mode to be over.
Closes #4200 (closed)