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_client.h

@@ -0,0 +1,40 @@
+#pragma once
+
+#include <boost/asio.hpp>
+#include <memory>
+#include <string>
+#include <thread>
+#include <mutex>
+#include <functional>
+
+using boost::asio::ip::tcp;
+
+// TCP Client class
+class TCPClient {
+public:
+    TCPClient(const std::string& host, int port);
+    ~TCPClient();
+
+    bool connect();
+    void disconnect();
+    void send(const std::string& message);
+    void send(const char* data, size_t size);
+    void setReceiveCallback(std::function<void(const std::string&)> callback);
+    void setReceiveCallback(std::function<void(const char*, size_t)> callback);
+
+private:
+    void start_read();
+    void handle_read(const boost::system::error_code& error, std::size_t bytes_transferred);
+
+    std::string host_;
+    int port_;
+    bool connected_;
+    boost::asio::io_context io_context_;
+    boost::asio::executor_work_guard<boost::asio::io_context::executor_type> work_;
+    std::shared_ptr<tcp::socket> socket_;
+    std::thread clientThread_;
+    std::mutex socketMutex_;
+    std::function<void(const std::string&)> receiveCallback_;
+    std::function<void(const char*, size_t)> receiveCallbackBytes_;
+    std::vector<char> buffer_;
+};