Mollie API 4.0.0.0

Breaking changes:

• Updated various namespaces of request and response models so they match the folder structure of the project.
• Updated the BalanceClient.GetBalanceTransactionListAsync and BalanceClient.GetPrimaryBalanceTransactionListAsync methods to use a ListResponse type instead of a custom response type, so they are consistent with other API clients.
• Removed the optional retry policy parameter from the Mollie.Api.DependencyInjection.AddMollieApi extensions method. A retry policy can now only be configured through the MollieOptions.RetryPolicy property.
• Renamed all API clients to consistently use singular names. For example, the ChargebacksClient has been renamed to ChargebackClient.
• Renamed the BalanceClient.ListBalancesAsync method to BalanceClient.GetBalanceListAsync so the naming is consistent with other API clients.
• Renamed the CaptureClient.GetCapturesListAsync method to CaptureClient.GetCaptureListAsync so the naming is consistent with other API clients.
• Renamed the ShipmentClient.GetShipmentsListAsync method to ShipmentClient.GetShipmentListAsync so the naming is consistent with other API clients.
• Renamed the PaymentClient.DeletePaymentAsync method to PaymentClient.CancelPaymentAsync so the naming is consistent with the Mollie API reference.
• Renamed the RefundClient.CreateRefundAsync method to RefundClient.CreatePaymentRefundAsync so the naming is consistent with the Mollie API reference.
• Renamed the RefundClient.GetRefundListAsync method to RefundClient.GetPaymentRefundListAsync so the naming is consistent with the Mollie API reference.
• Renamed the RefundClient.GetRefundAsync method to RefundClient.GetPaymentRefundAsync so the naming is consistent with the Mollie API reference.
• Renamed the RefundClient.CancelRefundAsync method to RefundClient.CancelPaymentRefundAsync so the naming is consistent with the Mollie API reference.
• Moved the OrderClient.CreateOrderRefundAsync and the OrderClient.GetOrderRefundListAsync methods from the OrderClient class to the RefundClient class to be consistent with the Mollie API reference.
• Created payment method specific return types when creating a mandate for a specific payment type. For example, when creating a PaypalMandateRequest, the response will now be a PaypalMandateResponse that can contain PayPal specific information in the PaypalMandateResponse.Details property. For a full list of payment method specific mandate response types, take a look at the updated documentation of the MandateClient.

New features:

• Enabled nullable reference types in project. All models now indicate which properties are nullable and which properties are non-nullable. This means you no longer have to lookup this information in the Mollie API documentation.
  
• Added the required keyword for request properties that are required by the Mollie API, so you cannot forget to initialize required properties.