[CPP]. Optimizing Build Targets and Build Process

[ColinLeeo]

In the CPP project build, the following issues need to be addressed:

1. gtest should be introduced to the repository as a third-party compressed package, without the need for downloading during the build process.
2. Files that have already been downloaded should be checked to ensure they are not downloaded again unnecessarily.
3. CPP header files need to be placed under the include directory. Currently, header files are directly referenced from the source code directory, which is unreasonable.
4. Build scripts should include more interactive explanations.
5. Allow users to compile and produce artifacts with full static linking, dynamic linking, and compressed static linking.
6. Allow users to specify encoding compression dependencies during the build.