Improvement for the screenshot capture feature by using a web worker to process the differences between the screenshots, and some code adjustments.

Remove flow-related packages
Remove type annotations from JS files

Changed screen capture to non effect. Effects are used to alter the stream, this feature does not need to alter the stream, it just needs access to it

Changed image diff library. Previous library diff’ed the whole image, the new one has en early return threshold

Use ImageCaptureAPI to take the screenshot. Added polyfill for it and polyfill for createImageBitmap

Added analytics