Introduce ClHHP headers version

OpenCL CLHPP headers don't have any version information inside them. E.g. the package itself is released as v2024.10.24, but how can I extract this information from headers?

Sometimes, we need to write conditional code which depends on availability of some C++ OpenCL API, but it's impossible to do it, because headers don't have version information.

The issue names no specific file or test; start by locating the OpenCL C++ header definitions and checking how the v2024.10.24 package version is represented. Done means the headers expose version information that client code can use for conditional API checks.

Written by the indexing model from the issue text.