Add initial implementation of ConnectTool with Dear ImGui and Steam Networking

- Created project files for ConnectTool including filters and user settings.
- Added README.md with setup instructions and prerequisites for building the project.
- Implemented imgui_hello.cpp as a simple Dear ImGui application using GLFW and OpenGL.
- Developed online_game_tool.cpp for hosting and joining game rooms using Steam Networking.
- Created p2p_chat.cpp for a peer-to-peer chat application utilizing Steam Networking.
- Implemented steam_friends.cpp to display the user's Steam friends list.
- Added TCP client and server classes for handling network communication.
- Integrated TCP server and client functionality into online_game_tool for real-time data exchange.

tcp/tcp_server.h

@@ -0,0 +1,45 @@
+#pragma once
+
+#include <boost/asio.hpp>
+#include <memory>
+#include <vector>
+#include <string>
+#include <thread>
+#include <mutex>
+#include <isteamnetworkingsockets.h>
+#include <isteamnetworkingutils.h>
+#include <steamnetworkingtypes.h>
+
+using boost::asio::ip::tcp;
+
+// Extern declarations for global variables used in TCPServer
+extern HSteamNetConnection g_hConnection;
+extern bool g_isConnected;
+extern ISteamNetworkingSockets* m_pInterface;
+extern bool forwarding;
+
+// TCP Server class
+class TCPServer {
+public:
+    TCPServer(int port);
+    ~TCPServer();
+
+    bool start();
+    void stop();
+    void sendToAll(const std::string& message, std::shared_ptr<tcp::socket> excludeSocket = nullptr);
+    void sendToAll(const char* data, size_t size, std::shared_ptr<tcp::socket> excludeSocket = nullptr);
+    int getClientCount();
+
+private:
+    void start_accept();
+    void start_read(std::shared_ptr<tcp::socket> socket);
+
+    int port_;
+    bool running_;
+    boost::asio::io_context io_context_;
+    boost::asio::executor_work_guard<boost::asio::io_context::executor_type> work_;
+    tcp::acceptor acceptor_;
+    std::vector<std::shared_ptr<tcp::socket>> clients_;
+    std::mutex clientsMutex_;
+    std::thread serverThread_;
+};