ONVIF Support

[rjsachse]

I integrated my previous ONVIF code and tested it using ODM (ONVIF Device Manager) and Agent DVR. The basic functionality is operational, as it processes requests and responds accordingly. However, I am hesitant to submit a pull request because I need assistance in finalizing the XML responses for various features. Additionally, I lack the necessary peripherals, such as pan-and-tilt servos, and I do not own any ONVIF recorders. I initially embarked on this implementation at the request of a user. Hence, I created RTSP Server library to use with ONVIF for Video, Audio & Subtitles

I am seeking advice on the best approach to collaborate with users to complete the XML responses.