GdkWin32: Configure as needed when going fullscreen

GdkWin32: Configure as needed when going fullscreen

Apply the fixes made by Chun-Wei Fan in [1] also for fullscreening /
unfullscreen. Fixes https://gitlab.gnome.org/GNOME/gtk/-/issues/4631

Also set the SWP_FRAMECHANGED flag as written by Raymond Chen in "How
do I switch a window between normal and fullscreen?" [2]

> An important flag to pass here is SWP_FRAME­CHANGED, which tells
> the window manager to recalculate the window decorations (which we
> need it to do because we just changed them).

References:
[1] - https://gitlab.gnome.org/GNOME/gtk/-/merge_requests/3712
[2] - https://devblogs.microsoft.com/oldnewthing/20100412-00/?p=14353