MULE-8044 - fixing transfer encoding chunked for listneer

forceWorkManagerUsage() is used as a hint to do process in the current thread. supportsAsynchronousProcessing() defines if the message processing can be done in a different thread than the current one which is different from the former. So if forceWorkManagerUsage() is false, phases can do processing in the current thread unless there's a good reason for not doing so, as in throttling were in the case of a delay policy it will free the current thread and continue execution later in a different thread. In the case of flow processing there's no reason to leave the current thread (all flow processing is sync today) so it will use the current thread.