listDevices method
Lista todos os dispositivos USB disponÃveis
Implementation
@override
Future<List<UsbDeviceInfo>> listDevices() async {
final result = await methodChannel.invokeMethod<List>('listDevices');
if (result == null) return [];
return result
.map((item) => UsbDeviceInfo.fromMap(item as Map<dynamic, dynamic>))
.toList();
}