CompleteOrderRequest doesn't offer the ability to return the payment information

[glennjacobs]

CompleteOrderRequest extends FetchOrderRequest, but as it implements its own sendData() method, we cannot opt to include the payment information in the response.

See https://github.com/thephpleague/omnipay-mollie/blob/master/src/Message/Request/CompleteOrderRequest.php#L42-L47

Ideally it should work similar to https://github.com/thephpleague/omnipay-mollie/blob/master/src/Message/Request/FetchOrderRequest.php#L42-L54