Add retry configuration for payment requests with Dunning and Downtime classes

src/CheckoutSdk/Payments/Downtime.cs

@@ -0,0 +1,11 @@
+namespace Checkout.Payments
+{
+    public class Downtime
+    {
+        /// <summary>
+        /// Indicates if Checkout.com retries the payment when it's declined due to issuer or acquirer downtime
+        /// (Required)
+        /// </summary>
+        public bool Enabled { get; set; }
+    }
+}

src/CheckoutSdk/Payments/Dunning.cs

@@ -0,0 +1,16 @@
+namespace Checkout.Payments
+{
+    public class Dunning
+    {
+        /// <summary>
+        /// Indicates if Checkout.com retries the payment when it's declined with a supported decline code (Required)
+        /// </summary>
+        public bool Enabled { get; set; }
+
+        /// <summary> (Optional, [ 1 .. 15 ], default: 6) </summary>
+        public int? MaxAttempts { get; set; } = 6;
+
+        /// <summary> (Optional, [ 1 .. 60 ] default: 30) </summary>
+        public int? EndAfterDays { get; set; } = 30;
+    }
+}

src/CheckoutSdk/Payments/Request/PaymentRequest.cs

@@ -72,10 +72,10 @@ public class PaymentRequest
 
         public IList<Product> Items { get; set; }
 
-        public PaymentRetryRequest Retry { get; set; }
+        public RetryRequest Retry { get; set; }
 
         public IDictionary<string, object> Metadata { get; set; } = new Dictionary<string, object>();
 
         public PaymentInstruction Instruction { get; set; }
     }
-}
+}

src/CheckoutSdk/Payments/RetryRequest.cs

@@ -0,0 +1,11 @@
+namespace Checkout.Payments
+{
+    public class RetryRequest
+    {
+        /// <summary> Configuration of asynchronous Dunning retries (Optional) </summary>
+        public Dunning Dunning { get; set; }
+
+        /// <summary> Configuration of asynchronous Downtime retries (Optional) </summary>
+        public Downtime Downtime { get; set; }
+    }
+}