[v25r0] Run ddsim with root6 and additional init-stript

• Need to pick up more G4Data variables for geant 10.2. On cvmfs all versions of the data files are in the same folder, so we cannot use ls -d to find the version, need to pick up the exact version in the tarball and add it to the CS instead. Keep backward compatibility for older versions, which still set G4DATA and pick up the folders from there.
• Root cling needs to find some header files, which can be described by CPATH
• pick up component and pcm files for the tarball, needed by gaudi plugin mechanisem for dd4hep with root 6

This is actually already running in production via a tag and ilcdirac release v25r0p7