Switch to CupertinoListSection/CupertinoListTile

[daniele-athome]

At last we can get rid of our custom implementations.

https://api.flutter.dev/flutter/cupertino/CupertinoListSection-class.html
https://api.flutter.dev/flutter/cupertino/CupertinoListTile-class.html

[daniele-athome]

I did some experiments and it turned out it requires a bit more work than I was expecting.