w32_common: refactor window resizing

Fixes lots of issues with current window resizing and window style
modifications.

Author: kasper93

DOCS/man/options.rst

@@ -3677,7 +3677,7 @@ Window
 ``--force-window-position``
     Forcefully move mpv's video output window to default location whenever
     there is a change in video parameters, video stream or file. This used to
-    be the default behavior. Currently only affects X11, macvk and SDL VOs.
+    be the default behavior. Currently only affects Windows, X11, macvk and SDL VOs.
 
 ``--auto-window-resize=<yes|no>``
     By default, mpv will automatically resize itself if the video's size changes