[modern-cpp-kafka] New port

[xiaozhuai]

• Changes comply with the maintainer guide
• The name of the port matches an existing name for this component on https://repology.org/ if possible, and/or is strongly associated with that component on search engines.
• Optional dependencies are resolved in exactly one way. For example, if the component is built with CMake, all find_package calls are REQUIRED, are satisfied by vcpkg.json's declared dependencies, or disabled with CMAKE_DISABLE_FIND_PACKAGE_Xxx
• The versioning scheme in vcpkg.json matches what upstream says.
• The license declaration in vcpkg.json matches what upstream says.
• The installed as the "copyright" file matches what upstream says.
• The source code of the component installed comes from an authoritative source.
• The generated "usage text" is accurate. See adding-usage for context.
• The version database is fixed by rerunning ./vcpkg x-add-version --all and committing the result.
• Only one version is in the new port's versions file.
• Only one version is added to each modified port's versions file.

Close #32897

[dg0yt]

I don't think this really needs a CMake project. You can just add a config file directly to the port and install from the portfile.

[xiaozhuai]

I don't think this really needs a CMake project. You can just add a config file directly to the port and install from the portfile.

@dg0yt
I know. But I prefer to provide a CMakeLists.

[xiaozhuai]

Usage passed on x64-osx with following demo code

set(CMAKE_CXX_STANDARD 17)

find_package(unofficial-modern-cpp-kafka CONFIG REQUIRED)
add_executable(test_kafka main.cpp)
target_link_libraries(test_kafka PRIVATE unofficial::modern-cpp-kafka::modern-cpp-kafka)

#include "kafka/AdminClient.h"
#include "kafka/Error.h"

int main() {
    kafka::Properties props;
    kafka::clients::admin::AdminClient client(props);
    return 0;
}

[MonicaLiu0311]

The usage test passed on x64-windows (header files found):

modern-cpp-kafka provides CMake targets:

    find_package(unofficial-modern-cpp-kafka CONFIG REQUIRED)
    target_link_libraries(main PRIVATE unofficial::modern-cpp-kafka::modern-cpp-kafka)