Fix ISF_HepMC_Tools tests
In this MR:
- Fix ISF_HepMC_Tools tests
- HepMC3 cleanup in ISF_HepMC_Tools
The fixes help to deal with the fact that eta() of particle with momenta (0,0,0) is infinity in HepMC3 but is finite in HepMC2. The problem with infinities is propagated to infinity-unaware code that makes comparisons.
Edited by Andrii Verbytskyi