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.

ConnectTool.vcxproj.filters

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <Filter Include="源文件">
+      <UniqueIdentifier>{4FC737F1-C7A5-4376-A066-2A32D752A2FF}</UniqueIdentifier>
+      <Extensions>cpp;c;cc;cxx;c++;cppm;ixx;def;odl;idl;hpj;bat;asm;asmx</Extensions>
+    </Filter>
+    <Filter Include="头文件">
+      <UniqueIdentifier>{93995380-89BD-4b04-88EB-625FBE52EBFB}</UniqueIdentifier>
+      <Extensions>h;hh;hpp;hxx;h++;hm;inl;inc;ipp;xsd</Extensions>
+    </Filter>
+    <Filter Include="资源文件">
+      <UniqueIdentifier>{67DA6AB6-F800-4c08-8B7A-83BB121AAD01}</UniqueIdentifier>
+      <Extensions>rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe;resx;tiff;tif;png;wav;mfcribbon-ms</Extensions>
+    </Filter>
+  </ItemGroup>
+</Project>