feat(restartIce)

[adwpc]

Description

add restartIce

Reference issue

Fixes #154
depend on #156

[adwpc]

Reference:
https://developer.mozilla.org/en-US/docs/Web/API/RTCOfferOptions/iceRestart

pc.oniceconnectionstatechange = function(evt) {
  if (pc.iceConnectionState === "failed") {
    if (pc.restartIce) {
      pc.restartIce();
    } else {
      pc.createOffer({ iceRestart: true })
      .then(pc.setLocalDescription)
      .then(sendOfferToServer);
    }
  }
}

[tarrencev]

lgtm! have you been able to test it? do we require any changes on the sfu side?

[adwpc]

In my test:
1 iceConnectionState changed to "disconnected" in 35s after i switched my network
2 restartIce will trigger onNegotiationNeeded(createOffer-->setLocalDescription-->signal.offer-->setRemoteDescription), signal should support reconnect first(jsonrpc and grpc :()
https://stackoverflow.com/questions/13797262/how-to-reconnect-to-websocket-after-close-connection
need this one: #156