HOTFIX: 2 New Extension Methods For .net Exception

Created two new extension methods (MessageClean & ToStringClean) that target the basic .net Exception. The methods currently mask any valid credit card information found before returning the results. Updated acerror.Show_Error to use these methods when logging/displaying results. Also create a new unit test to verify masking is taking place and helpers MaskAllCreditCardNumbersInString and ValidCreditCardNumbersFoundInString.