Right now this should not do anything because all windows are per-monitor DPI aware. When this is changed this will automatically fall back to window surface scaling through `NtGdiStretchBlt` in win32u.
This has the disadvantage that `NtGdiStretchBlt` is doing an absolutely terrible job at upscaling. This then adds a way for drivers to opt-in and do their own surface scaling before falling back to win32u. Alternatively and perhaps better, we could pull libcairo and use it to scale the surface contents with high quality filtering instead of using GDI.
-- v2: win32u: Implement DPI scaled window surface. win32u: Move window_surface creation helper to dce.c. win32u: Map window rects DPI before calling into the drivers. win32u: Map window region DPI before calling into the drivers. winex11: Use the driver rects to convert from host visible to window rect. winex11: Keep a window_rects struct in the driver window data. win32u: Move visible rect computation out of the drivers. win32u: Keep SetIMECompositionWindowPos with other IME entries.