Stops operation by request.

Parameters:

wsRequestId	(wstring) Request identifier of one of the operations, started before.
bWait	(boolean) Whether to wait for actual operation stop in blocking way (`true`) or just initiate asynchronous stop and return back ASAP (`false`).

Note:: Function does not throw an exception intentionally if wrong, inexistent or "expired" request id is used (just does nothing in this case).