[Feature] Support com.unity.webrtc

[martindevans]

com.unity.webrtc is a package for using webrtc within a Unity project. Investigate if this can be used as a free alternative to the current WebRTC P2P backend.

Notes:

• Unity package docs.
• Supports unreliable/unordered channels (RTCDataChannelInit)

[chrisk414]

It will be super awesome!
For bandwidth reasons, VOIP must use P2P and the only possible solution is to use WebRTC and it's super expensive and Steam is tied to Steam. Adding unity WebRTC will significantly increase the marketability and I would like to see this happen.
Thanks for the great work!