Fetch cardReference during completeAuthorize

[judgej]

If a card reference is being created when authorizing (by setting the createCard flag) then the card reference must be fetched as a separate request for all payment types except Payment Page.

This change is needed to avoid the need to make that second, explicit API call. During CompleteRequest::send() an API call is made to fetch the card details and supplement the data already returned to the merchant site with the end user. The createCard option needs to be set when completing the transaction in order to trigger this functionality.

[judgej]

Completed for the 2.x branch.

[judgej]

This should be extended to the notify message too, so the card reference is available to the back end without the need to perform an explicit separate request to get the reference.

[judgej]

Making an additional request in the complete response feels messy, since a new $gateway needs to be built to support it. But it seems to be the only way to do this. The request is only run on getCardReference().