Replace Native WebRTC implementation (?)

[ValorZard]

Right now we’re using https://github.com/sipsorcery-org/sipsorcery for our native implementation of WebRTC data channels. It has been fine so far, but looking at the git repository there are a couple of issues with their implementation.

Fortunatly, there has been a PR that claims to fix most of those issues sipsorcery-org/sipsorcery#1192, so if we can get that merged in, we are hunky dory.

in case that is still too slow, I could probably figure out a way to write c# bindings to lib data channel. (Maybe look at https://github.com/hanseuljun/datachannel-unity)