common: add paddle v1 api client

Streetwriters.Common/Models/RefundPaymentResponse.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Text.Json.Serialization;
+
+namespace Streetwriters.Common.Models
+{
+    public partial class RefundPaymentResponse
+    {
+        [JsonPropertyName("success")]
+        public bool Success { get; set; }
+
+        [JsonPropertyName("response")]
+        public Refund Refund { get; set; }
+    }
+
+    public partial class Refund
+    {
+        [JsonPropertyName("refund_request_id")]
+        public long RefundRequestId { get; set; }
+    }
+}