feat(Core/Packets): Port packet handling from TrinityCore (#5617)

* feat(Core/Packets): Port packet handling from TrinityCore

* 1

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* #3670

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* codestyle

* fix msvc warnings

src/server/game/Server/Packet.h

@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2016+ AzerothCore <www.azerothcore.org>, released under GNU AGPL v3 license: https://github.com/azerothcore/azerothcore-wotlk/blob/master/LICENSE-AGPL3
+ * Copyright (C) 2021+ WarheadCore <https://github.com/WarheadCore>
+ */
+
+#ifndef PacketBaseWorld_h__
+#define PacketBaseWorld_h__
+
+#include "WorldPacket.h"
+
+namespace WorldPackets
+{
+    class AC_GAME_API Packet
+    {
+    public:
+        Packet(WorldPacket&& worldPacket);
+
+        virtual ~Packet() = default;
+
+        Packet(Packet const& right) = delete;
+        Packet& operator=(Packet const& right) = delete;
+
+        virtual WorldPacket const* Write() = 0;
+        virtual void Read() = 0;
+
+        WorldPacket const* GetRawPacket() const { return &_worldPacket; }
+        size_t GetSize() const { return _worldPacket.size(); }
+
+    protected:
+        WorldPacket _worldPacket;
+    };
+
+    class AC_GAME_API ServerPacket : public Packet
+    {
+    public:
+        ServerPacket(OpcodeServer opcode, size_t initialSize = 200);
+
+        void Read() final;
+
+        void Clear() { _worldPacket.clear(); }
+        WorldPacket&& Move() { return std::move(_worldPacket); }
+        void ShrinkToFit() { _worldPacket.shrink_to_fit(); }
+
+        OpcodeServer GetOpcode() const { return OpcodeServer(_worldPacket.GetOpcode()); }
+    };
+
+    class AC_GAME_API ClientPacket : public Packet
+    {
+    public:
+        ClientPacket(WorldPacket&& packet);
+        ClientPacket(OpcodeClient expectedOpcode, WorldPacket&& packet);
+
+        WorldPacket const* Write() final;
+
+        OpcodeClient GetOpcode() const { return OpcodeClient(_worldPacket.GetOpcode()); }
+    };
+}
+
+#endif // PacketBaseWorld_h__