Add Netflix Addon to Mellow Player (Fix #266 (closed))

The user has to install qt5-webengine-widevine.

AUR: https://aur.archlinux.org/packages/qt5-webengine-widevine/
Ubuntu & others: It is a little bit more complicated but you can follow the code of qtwebflix.

Preview

ToDo

Fix the artwork.
Test it on other platforms (Windows and Mac)