Multi-language support + exit button fixed

[opti0]

Summary of changes:

• Updated project to .NET Framework 4.8.
• Added localization support using resource files (.resx).
• Translated the user interface into Polish.
• Improved behavior of the minimize and close buttons – the app now minimizes to the system tray when minimized, and the close button properly terminates the application.

[floviolleau]

Hi @opti0 ,

Thanks a lot for your contribution but to keep the project clean, please change all your comments into English as I don't speak polish.

Once you will be done, I will review the last changes you will make and I will merge to main branch.

Take care