test-auth: add example of how to remove sessions
test-auth: add example of how to remove sessions

Add an example of the session filter api.

thaytan/gst-rtsp-server,Lachann/gst-rtsp-server,surround-io/gst-rtsp-server,barisdemiray/gst-rtsp-server,surround-io/gst-rtsp-server,hsteinhaus/gst-rtsp-server,hsteinhaus/gst-rtsp-server,barisdemiray/gst-rtsp-server,thaytan/gst-rtsp-server,surround-io/gst-rtsp-server,Lachann/gst-rtsp-server,thaytan/gst-rtsp-server,Lachann/gst-rtsp-server,barisdemiray/gst-rtsp-server,hsteinhaus/gst-rtsp-server