Invert ToggleSwitch value interpretation

[kalpeshp0310]

Fixes #60

bool _enable = false;

@override
Widget build(BuildContext context) {
  Row(
    children: [
      TUIToggleSwitch(
        value: _enable,
        onChanged: (bool val) {
          setState(() {
            _enable = val;
          });
        },
      ),
      const SizedBox(
        width: 40,
      ),
      TUIToggleSwitch(
        value: _enable,
      ),
    ],
  ),
}

Will render the component like this now.