[UX] Users don't see the Screen Recording notification at all

[veler]

So many users ask how to take a screenshot of the app. They fail to see the notification we put in the bar.
Let's remove the ScreenRecordingProtectionSill and its related components, and let's show a Windows Toast Notification instead, that explain to the user that WindowSill won't appear in screenshot or video recording due to privacy setting that they can disable in Settings > General > Privacy. Ensure the notification shows up only once. Clicking the notification must navigate the user to the SettingsViewModel.GeneralPageInternalName page.