Extend generated <Project>Config.cmake with upstream versions
The generated <Project>Config.cmake
in enhanced with the exact versions of upstream (LHCb) projects so that we do not risk to build downstream projects with incompatible versions of projects upstream of the direct dependencies.
For example, if LHCb 53.3 is built against Gaudi 36.1, a local build of Lbcom requiring the released LHCb 53.3 should look for Gaudi 36.1, but at the moment it would try to use Gaudi 36.2 (with weird errors).
This MR fixes the problem for future releases