fixes https://github.com/flutter/flutter/issues/126679 

### Description
Control cupertino widgets like `CupertinoCheckbox` and `CupertinoRadio` have `focusNode` and `autofocus`, while these are missing in `CupertinoSwitch`.

This is blocking https://github.com/flutter/flutter/issues/126637 
(`switch.dart` currently maintains its focus node for `CupertinoSwitch` when using `Switch.adaptive` which causes a bug)