[window-state] The position looks odd when switching screens with various screen sizes

The window-state plugin saves the position as an absolute one.

Given this usecase:
* I have my macbook connected to external (large 5K) screen.
* **Center the app**, window state gets saved
* Disconnect large screen and switch to integrated small screen
* Open up the app, state is restored
* **The app is in the bottom right corner**

This also works the other way around. Centering on small screen moves the app to top left corner on large screen.

This not only looks odd, but also is a bad UX. Wouldn't it be better to have it as a relative screen position?