AI seeded comments from robch and then edited by stephentoub (#238)

* AI generated `///` comment updates

* Fix compilation issues

* Fix incorrect XML comment structure

* Update all Client comments

* Update all Configuration comments

* Update all Messages comments

* Update all Transport comments

* Update all Types comments

* Update all Server comments

* Undo some commenting

---------

Co-authored-by: Stephen Toub <stoub@microsoft.com>

src/Common/Polyfills/System/IO/TextWriterExtensions.cs

@@ -1,6 +1,3 @@
-using ModelContextProtocol.Utils;
-using System.Runtime.InteropServices;
-
 namespace System.IO;
 
 internal static class TextWriterExtensions

src/Common/Throw.cs

@@ -1,4 +1,4 @@
-using System.Diagnostics.CodeAnalysis;
+using System.Diagnostics.CodeAnalysis;
 using System.Runtime.CompilerServices;
 
 namespace ModelContextProtocol.Utils;
@@ -38,4 +38,4 @@ internal static class Throw
 
     [DoesNotReturn]
     private static void ThrowArgumentNullException(string? parameterName) => throw new ArgumentNullException(parameterName);
-}
+}