Add better listVideoInputDevices check in BrowserCodeReader.ts

[nicoesiea]

The function listVideoInputDevices (in the BrowserCodeReader.ts file) lists all the available video input devices. It could be nice to force the label with a known value to have a way to make a distinction with environemental and selfie camera.
I'm thinking on an example of code, like:

navigator.mediaDevices .enumerateDevices() .then(function (devices) {
  const videoDevices = devices.filter(
    (device) => device.kind === "videoinput"
  );
  videoDevices.forEach((device) => {

  navigator.mediaDevices
    .getUserMedia({ video: { deviceId: device.deviceId } })
    .then((stream) => {
      const track = stream.getVideoTracks()[0];
      const settings = track.getSettings();
      
      alert("Camera:" + device.label);
      alert("Settings:" + JSON.stringify(settings));

      // Hypothèse : the selfie camera are mirror option set
      if (settings.facingMode === "user") {
        alert("It seems this is selfie camera");
      } else if (settings.facingMode === "environment") {
        alert("It seems this is environmental camera.");
      } else {
        alert("Here we do not know.");
      }

      // Stop
      track.stop();
    })
    .catch((err) => {
      console.error("Error", device.deviceId, err);
    });
});
})
.catch(function (err) {
  console.error("Error to get the camera:" + err);
});

Maybe there is a better solution to do this check. I will be very happy to discover it.
Thank you in advance