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

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

* 1

* 2

* 3

* 1

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* #3670

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* 1

* codestyle

* fix msvc warnings

src/server/game/Server/Packet.cpp

@@ -0,0 +1,37 @@
+/*
+ * 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>
+ */
+
+#include "Packet.h"
+#include "Errors.h"
+
+WorldPackets::Packet::Packet(WorldPacket&& worldPacket) : _worldPacket(std::move(worldPacket))
+{
+}
+
+WorldPackets::ServerPacket::ServerPacket(OpcodeServer opcode, size_t initialSize /*= 200*/) : Packet(WorldPacket(opcode, initialSize))
+{
+}
+
+void WorldPackets::ServerPacket::Read()
+{
+    ASSERT(!"Read not implemented for server packets.");
+}
+
+WorldPackets::ClientPacket::ClientPacket(OpcodeClient expectedOpcode, WorldPacket&& packet) : Packet(std::move(packet))
+{
+    ASSERT(GetOpcode() == expectedOpcode);
+}
+
+WorldPackets::ClientPacket::ClientPacket(WorldPacket&& packet)
+    : Packet(std::move(packet))
+{
+}
+
+WorldPacket const* WorldPackets::ClientPacket::Write()
+{
+    ASSERT(!"Write not allowed for client packets.");
+    // Shut up some compilers
+    return nullptr;
+}