Giving the TransactionCode also in the result of the Fetch method

[Sina-Soltani]

The TransactionCode can be given to the user also in the result of the Fetch method. This can be added as a new Property in the PaymentFetchResult class. The value of the new property must be assigned where we check if the Payment is completed or not. When it's completed, then it's just an assignment like

fetchResult.TransationCode = payment.TransationCode;

[Sina-Soltani]

The discussion about this ticket #319