Always respond to 2c2p notification request

Problem/Motivation

As documented in commerce module, onNotify method should never throw exceptions and should always acknowledge receiving the notification; currently 2c2p keeps sending notification requests if the payment failed.

Attached a patch that keeps throwing PaymentGatewayException and logging it but catches it and returns 200 response code.
In addition, I added a check for the order state before creating the payment similar to what we have in onReturn method.