Add `IOCTL_WINEBTH_RADIO_START_AUTH`, which gets used to implement `BluetoothAuthenticateDeviceEx`.
-- v8: bluetoothapis/tests: Add tests for BluetoothAuthenticateDeviceEx. bluetoothapis: Use a wizard GUI to respond to pairing requests if an authentication callback is not registered. bluetoothapis: Implement BluetoothAuthenticateDeviceEx.