windows: More precise handling of `WM_SETTINGCHANGE` and appearance updates (#33829)
This PR adds more fine-grained handling of the `WM_SETTINGCHANGE`
message.
Plus, we now only trigger the `appearance_changed` callback when the
actual window appearance has changed, rather than calling it every time.
Release Notes:
- N/A
cdb7564d89张小白 committed on 7/3/2025, 9:27:27 AM· committed by GitHubparent968587a