[Feature] Dark Mode Support

[gashtal]

Would be valuable to have dark mode support in RapidCRC Unicode.

[OV2]

RapidCRC uses plain old win32 dialogs, which do not support any real dark mode. A redesign with a different GUI toolkit is unlikely.

[danielmmmm]

Could this project help? https://github.com/SFTRS/DarkTaskDialog

The "How to use" seems simple enough (presumed nothing goes wrong):

• Include DarkTaskDialog.hpp in your project.
• Call SFTRS::DarkTaskDialog::setTheme(dark|light) before displaying your first task dialog.
• Call the function again with the other theme when you need to switch it.