Implemented integration for the accepting payments using KNET debit cards
Updated DefaultCheckoutComGatewayWebhookHandler to support HOSTED_PAYMENT_PAGE_TRANSACTION_RESULTS notification type
Implemented a method DefaultCheckoutComGatewayWebhookHandler.shouldHandleRequest to check if the webhook event can be handled
Add a new interface com.broadleafcommerce.payment.service.gateway.constants.CheckoutComWebhookType to have the ability to add the new webhook event types
Replaced the DefaultCheckoutCom3DSTransactionLookupService with DefaultCheckoutComTransactionLookupService implementing the PaymentGatewayTransactionLookupService interface
In most ways, the implementations are identical, but with the inclusion of logic for KNET payments
Made the errorMessage param Nullable in DefaultCheckoutComTransactionService#buildExceptionPaymentResponse.
Added an error message and debug-level logging to TransactionResultsNotAvailableException in DefaultCheckoutComTransactionLookupService.
Removed warn-level logging from WebhookValidationException in DefaultCheckoutComGatewayWebhookHandler#validate and added an error message.
Added an error message to WebhookSignatureGenerationException in WebhookSignatureUtil#generateSignature
Added a GATEWAY_CREDENTIALS_ERROR with code 500 to CheckoutStatusCodesEnum.