Add ScreenTime permission

[sidan5]

Add the Screen Time permission into PermissionsSwiftUI's supported permissions. The Screen Time permission is needed to control screen time.

[N3v1]

Hey @sidan5,

I like the idea of your feature request, but there might not be an official way to achieve this. The ScreenTimeAPI can only block websites, and the STScreenTimeConfiguration is poorly documented and has no available methods to allow this behavior for non-apple (internal) apps.

If I am mistaken, I apologize.

https://developer.apple.com/documentation/screentime