fix: allow listPrice to be queried on CommerceOrder line items

[iskounen]

Description:
This PR allows us to query the listPrice field on an artwork when that artwork is a line item on a CommerceOrder from the stitched Exchange schema like so:

{
  commerceOrder(id: "2e8c7a62-37fe-4702-9e58-2227dd45e295") {
    lineItems {
      edges {
        node {
          artwork {
            listPrice {
              ... on PriceRange {
                display
              }
            }
          }
        }
      }
    }
  }
}

Before this change, the above query threw the following error because the PriceRange type was being transformed as part of the Exchange schema:

__typename did not match an object type: CommercePriceRange

See also:

• @zephraph => [KAWS] Fix stitching transform issue causing price fields to be renamed #1878