Migrating the InDetSimEventTPCnv TP Converters to work with the new transient HepMcParticleLink

This commit updates the TP converters in the `InDetSimEventTPCnv` package
to work with the new transient version of the `HepMcParticleLink` class.

All existing `InDetSimEventTPCnv` unit tests are updated to correctly set
the eventIndex property property of `HepMcParticleLinks` and check that
the event collection char member variable is set properly.