updateSettings new streaming parameters : trackSwitchMode and selectionModeForInitialTrack

Created by: jeffcunat

This PR adds two new settings parameters (may have been forgotten when new updateSettings function was created in v3)

{ streaming: 
  {
    trackSwitchMode: {audio: audioMode , video: videoMode},
    selectionModeForInitialTrack: mode,
  }
}

and deprecates setTrackSwitchModeFor and setSelectionModeForInitialTrack functions (still usable though)