[skyverge/wc-plugins#487] Redefine do_credit_card_transaction()

This change supports the Moneris efraud validation fix from
skyverge/wc-plugins#487 by adding an optional $response parameter, so
that the transaction can actually be performed outside of this method
(say in a child class's override) and pass in the response.

Although this is technically a backwards-incompatible change, at present
it's only the Moneris gateway itself that overrides the
do_credit_card_transaction() method.  Therefore, the only way a merchant
could get into trouble would be if they had both Moneris and another
frameworked payment gateway installed AND they updated the other payment
gateway AND the other payment gateway had this newer version of the
framework included.  seems like an acceptable level of risk

Author: justinstern

woocommerce/payment-gateway/class-sv-wc-payment-gateway-direct.php

@@ -616,15 +616,18 @@ protected function do_check_transaction( $order ) {
 	 *
 	 * @since 1.0.0
 	 * @param WC_Order $order the order object
+	 * @param SV_WC_Payment_Gateway_API_Response $response optional credit card transaction response
 	 * @return SV_WC_Payment_Gateway_API_Response the response
 	 * @throws SV_WC_Payment_Gateway_Exception network timeouts, etc
 	 */
-	protected function do_credit_card_transaction( $order ) {
+	protected function do_credit_card_transaction( $order, $response = null ) {
 
-		if ( $this->perform_credit_card_charge() ) {
-			$response = $this->get_api()->credit_card_charge( $order );
-		} else {
-			$response = $this->get_api()->credit_card_authorization( $order );
+		if ( is_null( $response ) ) {
+			if ( $this->perform_credit_card_charge() ) {
+				$response = $this->get_api()->credit_card_charge( $order );
+			} else {
+				$response = $this->get_api()->credit_card_authorization( $order );
+			}
 		}
 
 		// success! update order record