Some small changes to help usability:
- Add ParticleID, which is a combination of Cut2D and NuclearData to the nuclear module. Previously this was in Spyral, but it makes more sense to be here.
- Remove momentum module, and replace with a dependency on the vector package. They support way more advanced vector-analysis than what we could support, so make for a much improved solution over our custom one.
Documentation is updated and dependencies are somewhat cleaned up for the development side.