Windows: replace struct interface with one from crate

[i10416]

I replaced the temporary struct with one from crate in windows/dark-mode.rs according to comment.

• Tested on all platforms changed
• Compilation warnings were addressed
• cargo fmt has been run on this branch
• cargo doc builds successfully
• [] Added an entry to CHANGELOG.md if knowledge of this change could be valuable to users
• Updated documentation to reflect any user-facing changes, including notes of platform-specific behavior
• Created or updated an example program if it would help users understand this functionality
• Updated feature matrix, if new features were added or implemented

[maroider]

Thanks for taking the time to contribute.

However, the change you've proposed is already being undertaken as a part of #2011.