[UX] Implementation of Logout / Switch Account Button

[DarksAces]

📝 Description

Currently, switching Spotify accounts requires the user to manually delete the .cache file from the application folder. Adding a dedicated "Logout" button would streamline this process and improve the overall User Experience.

✨ Key Features

• Logout Button: Add a button in the sidebar or "Home" section.
• Session Clearing: Automatically delete the .cache file (or the file specified in SpotifyOAuth).
• App Restart: Restart the application or re-trigger the authentication flow after logout.

🛠 Technical Details

• Logic: os.remove(".cache") followed by a restart of the SpotifyToolkitApp instance.
• Safety: Add a confirmation dialog ("Are you sure you want to log out?") to prevent accidental clicks.