Updated Xml.DelegatingXmlReader to support close and ReadContentAsUni…

…queId

src/Microsoft.IdentityModel.Xml/DelegatingXmlDictionaryReader.cs

@@ -256,6 +256,15 @@ public override XmlSpace XmlSpace
             get => UseInnerReader.XmlSpace;
         }
 
+        /// <summary>
+        /// Closes the reader and changes the System.Xml.XmlReader.ReadState
+        /// to Closed.
+        /// </summary>
+        public override void Close()
+        {
+            UseInnerReader.Close();
+        }
+
         /// <summary>
         /// Gets the value of the InnerReader's attribute at the given index.
         /// </summary>
@@ -419,6 +428,14 @@ public override int ReadContentAsBinHex(byte[] buffer, int index, int count)
             return UseInnerReader.ReadContentAsBinHex(buffer, index, count);
         }
 
+        /// <summary>
+        /// Reads the content and returns the contained string.
+        /// </summary>
+        public override UniqueId ReadContentAsUniqueId()
+        {
+            return UseInnerReader.ReadContentAsUniqueId();
+        }
+
         /// <summary>
         /// Resolves the InnerReader's EntityReference nodes.
         /// </summary>