NEWT:

On the MacOS and iOS,
window units are used for the native UI component's position and size.
Here the surface size in pixel units = window-units-size * pixelScale.
This has been implemented already.

On Windows-GDI and X11,
pixel units are used for the native UI component's position and size.
Here we need to convert NEWT's window position and size
to and from the pixel-size, i.e. window units = pixel-units / pixelScale.

Hence all NEWT window-unit position and size values must
be appropriately converted from/to window-units on Windows and X11.

WIP ..