Update NodeID sample comment (#1820)

The sample included a fully named NodeId but the Format() uses the information already included in the instance. It might be easier to understand, if there is another sample and a node. Thus we can avoid confusion.

Stack/Opc.Ua.Core/Types/BuiltIn/ExpandedNodeId.cs

@@ -500,8 +500,19 @@ internal string IdentifierText
         /// NodeId = "hello123"<br/>
         /// NamespaceUri = "http://mycompany/"<br/>
         /// <br/> This would translate into:<br/>
-        /// nsu=http://mycompany/;str=hello123
-        /// <br/></para>
+        /// nsu=http://mycompany/;s=hello123
+        /// <br/>
+        /// </para>
+        /// <para>
+        /// NodeId = 5<br/>
+        /// NamespaceIndex = 2<br/>
+        /// <br/> This would translate into:<br/>
+        /// ns=2;i=5
+        /// <br/>
+        /// </para>
+        /// <para>
+        /// Note: Only information already included in the ExpandedNodeId-Instance will be included in the result
+        /// </para>
         /// </remarks>
         public string Format()
         {