Add support for CPack, allowing easy creation of RPM and DEB packages

[Edward-Elric233]

I have been considering manually packaging libhv into RPM and DEB packages for a while. Recently, due to work requirements, I learned about the Infinity project and discovered that CMake can directly use CPack for packaging. By adding just a few descriptive statements in the CMakeLists.txt file, RPM, DEB, and TGZ packages can be generated in the build directory by executing the cpack command. These packages can be placed in the Release section, allowing users to install and use libhv easily through their package manager, eliminating the need for manual compilation.

$ mkdir build
$ cd build
$ cmake ..
$ cmake --build .
$ cpack
$ ls libhv-*
libhv-1.0.0-x86_64.deb  libhv-1.0.0-x86_64.rpm  libhv-1.0.0-x86_64.tar.gz

Users can download the packages. For example, on Fedora/RHEL/CentOS/OpenSUSE systems:

wget https://github.com/Edward-Elric233/libhv/releases/download/v1.3.3/libhv-1.0.0-x86_64.rpm
sudo rpm -ivh libhv-1.0.0-x86_64.rpm

After installation, users can utilize the libhv headers and libraries for development.

I would be sincerely grateful if you could review this PR and provide any feedback or suggestions for improvement. Thank you for your time and attention.

[ithewei]

I recommend using ${PROJECT_VERSION} here.

[Edward-Elric233]

Sure, I'll update the CMakeLists.txt to use ${PROJECT_VERSION} for the CPACK_PACKAGE_VERSION. Thanks for the recommendation!