Release Notes for 1.5.6-GA

Updated the population of PaymentResponse#gatewayTransactionId to prefer the latest request id (i.e. the latest API request id), followed by the id of the relevant PaymentIntent, Charge, Refund, or Event.

Introduced logic to the Authorize and AuthorizeAndCapture interactions to populate PaymentResponse#recommendedSavedPaymentMethodStatus.

Updated mapping of Stripe response codes to Broadleaf transaction failure types so that no_account, account_closed, & payment_method_unsupported_type all map to INVALID_PAYMENT_METHOD.

Introduced support for sending the custom ACH mandate confirmation notifications