[CMAKE] make install does not install senconv headers

[marcalff]

With CMake, make install does not install all the semantic convention header files.

[marcalff]

FYI @dbarker , if you have any guildelines how to fix this.

[dbarker]

@marcalff Thanks for reporting. I just took a look and verified the semconv headers install locally when I run ./ci/do_ci.sh cmake.install.test which executes make install. Can you share more about which files are missing after install?