Add BatchId to InvokeReferences; clean up property layout

Added BatchId property to InvokeReferences for batch identification.
Refactored Reference3-5 property declarations for clarity and
consistency by removing unnecessary line breaks.

src/ReC.Client/Api/InvokeReferences.cs

@@ -5,6 +5,13 @@ namespace ReC.Client.Api
     /// </summary>
     public class InvokeReferences
     {
+        /// <summary>Batch identifier.</summary>
+        public string
+#if NET
+            ?
+#endif
+            BatchId { get; set; }
+
         /// <summary>Reference value 1.</summary>
         public string
 #if NET
@@ -21,7 +28,6 @@ namespace ReC.Client.Api
 
         /// <summary>Reference value 3.</summary>
         public string
-
 #if NET
             ?
 #endif
@@ -29,7 +35,6 @@ namespace ReC.Client.Api
 
         /// <summary>Reference value 4.</summary>
         public string
-
 #if NET
             ?
 #endif
@@ -37,7 +42,6 @@ namespace ReC.Client.Api
 
         /// <summary>Reference value 5.</summary>
         public string
-
 #if NET
             ?
 #endif