Fix taskbar widget song text and buttons

[Yorzaren]

Summary

Judging from the conversation in #537 the intended behavior is for the Taskbar Widget to follow Windows theming and not the FluentFlyout app theme. This adds a reg check to determine user's settings. It also fixes what I think is a bug where the Media Player buttons followed the FluentFlyout App theme settings. Now both of them will respect the Windows custom theme settings.

Motivation

Closes #614, #513
Supersedes #537

Type of Change

• Feature
• Bug fix
• Refactor (no functional changes)
• Style (formatting, naming)
• Other

What Changed

• Moved to using a Registry Check instead of WindowsThemeHelper to detect user themes.
• Made the Taskbar Widget player buttons follow system settings similar to the song text rather than FluentFlyout app theme.

Additional Information

• I've only checked the changes for Windows 11. Reg key should be the same in Windows 10, but I don't have Win10 box to check.

Checklist

• Code changes are manually tested and working.
• Formatting and naming are consistent with the project.
• Self-review of changes is done.

• AI tools were used (if yes, I reviewed and fully understand the changes myself).

[unchihugo]

Hi @Yorzaren, thank you for contributing!

From my testing, your changes do enable the taskbar widgets to properly change colors to match custom Windows theming now, since you're looking at the System theme value in registry.

Great work!