Add last four of credit card to PLS receipts so that we can easily identify POS transactions in the Transaction list.

When doing refunds, we sometimes have to look in the Transaction List to find the transaction. Normally we assign a transaction to a player profile. If no profile then we look at the Transaction List. However, when we pull up the transaction from the Transaction List there is no way to confirm that the transaction belongs to a particular receipt. If the last four of the CC used was on the list we could match that against the actual customer receipt. The last 4 of the cc is on the customers receipt.