Add motion detection into ONVIF profile

[0xgrm]

Thanks for this alternative firmware, it's working very good on my Yi Home 1080p.

I am exposing it to Scrypted with the ONVIF profile. Unfortunately it does not contain motion detection information.

I am currently publishing this information to MQTT and it's working great but it would be great to be able to add the motion detection to ONVIF, if possible.