从Serein.Library分离了WebSocket/Modbus；新增了Json门户类，用于未来的Http、WebSocket、Mqtt、gRPC、QUIC扩展。

Library/Network/Http/SereinExtension.cs

@@ -1,13 +1,6 @@
-using Newtonsoft.Json.Linq;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace Serein.Library.Network.Http
+namespace Serein.Library.Network.Http
 {
-    internal static partial class SereinExtension
+    /*internal static partial class SereinExtension
     {
         #region JSON相关
 
@@ -60,5 +53,5 @@ namespace Serein.Library.Network.Http
             }
         } 
         #endregion
-    }
+    }*/
 }