Update PaymentSessionsRequest.cs (#411)

- adds capture_on

Author: armando-rodriguez-cko

src/CheckoutSdk/Payments/Sessions/PaymentSessionsRequest.cs

@@ -66,6 +66,8 @@ public class PaymentSessionsRequest
         public PaymentSender Sender { get; set; }
 
         public bool? Capture { get; set; }
+        
+        public DateTime? CaptureOn { get; set; }
 
         public string IpAddress { get; set; }