Debugging symbols are missing

For some reason we have debugging symbols completely disabled in our release builds. This makes it many times harder to analyse core files generated by users. At most the debugging symbols cause a 1% performance difference so there is no good reason to disable them.

To fix this we need to do the following:

• Update CMakeLists.txt in the engine tree so that we do "-g" instead of "-g0"
• Confirm rpmbuild doesn't strip the CentOS binaries, we can either disable CPACK_STRIP_FILES or enable debuginfo packages if it does (https://gitlab.kitware.com/cmake/cmake/issues/15668)