Dump of simulation glossary from concept document

This is a copy of the glossary from the simulation concept document with minimal adjustments to be merged with the computing glossary in https://gitlab.cta-observatory.org/cta-computing/documentation/cta-computing-glossary

Don't think we should spend a lot of time on it, but simply decide if we this is in a stage to be integrated into the computing glossary. If you think this is the case, then please review it positively :-)

I think we mostly follow the concept of the glossary in the use cases, with some exceptions (e.g., introduced a simulation production package)