Canvas rendering does not work as expected on Safari - the image stays
still on the first frame. Calling play() on the video tags seems to help.

Do not resize the desktop share to 720p by default when the desktop track resolution is higher than 720p. This is causing bluriness when presenter is turned on.
Remove the 'detail' contentHint setting for the desktop+presenter canvas stream as it forcing chrome to send only 5 fps stream for high resolution desktop tracks.
Move the desktop resizing logic behind a config.js option - videoQuality.resizeDesktopForPresenter.

I don't know how to modify built-in MediaStreamTrack type, so ignore the error.

...so that the text is more readable in the presenter mode. Chrome by
default uses 'detail' for screen sharing. I went with the 'text' here,
because the docs[1] say "may take advantage of encoder tools that
optimize for text rendering." - whether that's good specifically for
the presenter mode I don't know. It looked good for me when tested
on Chrome.

https://www.w3.org/TR/mst-content-hint/

* Update JitsiStreamPresenterEffect.js
Create/terminate the Web Worker on effect start/stop so that we don't leak them.

On electron 7 drawing on hidden canvas will trigger a memory leak.
Not appending the canvas for the DOM seems to solve the problem.

- Adds the ability to share video as a "PiP" when screenshare is in progress.
- Add a method for creating a local presenter track.
- Make sure isLocalVideoTrackMuted returns the correct mute state when only screenshare is present.
- Make sure we get the updated window size of the window being shared before painting it on the canvas.
- Make sure we check if the shared window has been resized