第一批重构，主要是物理迁移脚本和部分命名空间的调整

- 结构上迁移文件，将脚本分成 Base/Runtime/Presentation/Procedure/Editor 五大文件夹
- 调整 DataTable 和 Definition 下脚本的命名空间
- 依据 UI-5层架构设计规范 拆分原先的 UI 到 Runtime 和 Presentation 下

Assets/GameMain/Scripts/Runtime/BuiltinComponent/Network/PacketBase.cs

@@ -0,0 +1,32 @@
+//------------------------------------------------------------
+// Game Framework
+// Copyright © 2013-2021 Jiang Yin. All rights reserved.
+// Homepage: https://gameframework.cn/
+// Feedback: mailto:ellan@gameframework.cn
+//------------------------------------------------------------
+
+using GameFramework.Network;
+using ProtoBuf;
+
+namespace StarForce
+{
+    public abstract class PacketBase : Packet, IExtensible
+    {
+        private IExtension m_ExtensionObject;
+
+        public PacketBase()
+        {
+            m_ExtensionObject = null;
+        }
+
+        public abstract PacketType PacketType
+        {
+            get;
+        }
+
+        IExtension IExtensible.GetExtensionObject(bool createIfMissing)
+        {
+            return Extensible.GetExtensionObject(ref m_ExtensionObject, createIfMissing);
+        }
+    }
+}