Add the ability to include gift certificate usage in reports

I know that there is a separate report that you can get the gift certificate information. We would like to run a single report that includes the what portion of an order is paid with a gift certificate.

This is needed because we have a customer who has a site that primarily contains inventory items. They issue credits (gift certificates) to their users to use on the site. Their users are able to pay any remaining balance with a credit card. When they do, we need to reimburse our customer that amount (minus our fees).

Currently, we have to generate two reports and combine them manually. Please add this ability sooner than later.