[reSIProcate] b-webrtc merged into main

[Daniel Pocock]

The b-webrtc branch has been merged into main now

The CI build (which also runs test cases in a clean disposable VM)
succeeds too

There is still work to be done on the WebSocket support, but that will
now happen in main.  However, it does run well enough that people can
register and make calls through repro using either SIPml5 or JsSIP.

Things like mutual certificate authentication should just work for WSS
because it shares the regular TLS transport code.