Async notifier for frame received event.
Functions using this handler:
This handler allows you to control received frames from remote peers. channel parameter is the channel where the frame was received. connection parameter represent the connection where the channel is running. Finally, user_data, is a user defined pointer passed in to this function and defined when the handler was registered.
You must not free received frame. Vortex library will do it for you. Remember that, if you want to have permanent access to frame payload, make a copy. After running this handler, Vortex library will free all VortexFrame resources.