The WM_DPICHANGED suggested RECT is calculated for non-maximized
windows. When a maximized window's DPI changes, we now query the
monitor's work area directly to ensure the window correctly fills the
entire screen.

For non-maximized windows, the original behavior using the
system-suggested RECT is preserved.

Release Notes:

- windows: Fixed maximized window size when DPI scale changes

Signed-off-by: Xiaobo Liu <cppcoffee@gmail.com>