Add support for refunding split payments

src/Mollie.Api/Models/Refund/Request/RefundRequest.cs

@@ -1,4 +1,5 @@
-using Mollie.Api.JsonConverters;
+using System.Collections.Generic;
+using Mollie.Api.JsonConverters;
 using Newtonsoft.Json;
 
 namespace Mollie.Api.Models.Refund.Request {
@@ -26,6 +27,20 @@ public record RefundRequest {
         /// </summary>
         public bool? Testmode { get; set; }
 
+        /// <summary>
+        /// If you wish to pull back the money that was sent to connected accounts within the creation of a partial
+        /// refund (namely a refund of less of the amount of the original payment), you can do so by setting the
+        /// routingReversals array in the request
+        /// </summary>
+        public IList<RoutingReversal>? RoutingReversals { get; set; }
+
+        /// <summary>
+        /// For a full reversal of the split that was specified during payment creation, simply set reverseRouting=true
+        /// when creating the refund, so that a full compensation is created for every route of the original payment.
+        /// This flag only works with full refunds, namely a refund of the same amount (or more) than the original payment.
+        /// </summary>
+        public bool? ReverseRouting { get; set; }
+
         public void SetMetadata(object metadataObj, JsonSerializerSettings? jsonSerializerSettings = null) {
             Metadata = JsonConvert.SerializeObject(metadataObj, jsonSerializerSettings);
         }

src/Mollie.Api/Models/Refund/Response/RefundResponse.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using Mollie.Api.JsonConverters;
 using Newtonsoft.Json;
 
@@ -55,6 +56,13 @@ public record RefundResponse {
         /// </summary>
         public required string PaymentId { get; set; }
 
+        /// <summary>
+        /// If you wish to pull back the money that was sent to connected accounts within the creation of a partial
+        /// refund (namely a refund of less of the amount of the original payment), you can do so by setting the
+        /// routingReversals array in the request
+        /// </summary>
+        public IList<RoutingReversal>? RoutingReversals { get; set; }
+
         /// <summary>
         /// Provide any data you like, for example a string or a JSON object. We will save the data alongside the refund. Whenever
         /// you fetch the refund with our API, we’ll also include the metadata. You can use up to approximately 1kB.

src/Mollie.Api/Models/Refund/RoutingReversal.cs

@@ -0,0 +1,15 @@
+using Mollie.Api.Models.Payment;
+
+namespace Mollie.Api.Models.Refund;
+
+public record RoutingReversal {
+    /// <summary>
+    /// The amount to refund to the source
+    /// </summary>
+    public required Amount Amount { get; init; }
+
+    /// <summary>
+    /// The source to which the amount should be refunded
+    /// </summary>
+    public required RoutingDestination Source { get; init; }
+}