The behavior of `window.cursor_position()` is not same cross platforms when enable cursor hittest

[lewiszlw]

Bevy version

0.10

[Optional] Relevant system information

OS: Win10 & MacOS

What you did

When enable cursor hittest in window_fallthrough example,

• On Win10, window.cursor_position() will always return None
• On MacOS, window.cursor_position() will return Some if inside window, or None if outside window

What went wrong

The behavior is not same cross platforms.