Create QNAM for each mjpeg stream

only to debug issue for one of customers
Add an option to enable/disable vaapi decoding in event player

Signed-off-by: Piotr Galiszewski <pgaliszewski@corp.bluecherry.net>
Debian: remove conflict with gstreamer-vaapi

Signed-off-by: Piotr Galiszewski <pgaliszewski@corp.bluecherry.net>