FEAT: Implement batch calculations for ase calculators

[TobiasDijkhuis]

Reopening same changes from #407, but rebased on develop branch

Using this change, it would be possible to calculate the forces of both dimer structures, or all NEB images at the same time using an NEB calculator, by putting another function in the same file as ase_calc and _calculate.

def batch_calculate(R, atomicNrs, boxes, calc):
    # --- customize this section ---
    return energies, forces

I would also like the option to somehow do this using pyeonclient's potential_from_calc*, but this will do for now 😄

I am not the most experienced in C++, so please let me know if I need to change anything.

*Perhaps by checking for a _batch_calculate method that takes the same arguments? This method would then set up the data (e.g. construct ase.Atoms from the positions, numbers, etc) and call whichever function the Calculator actually uses to do batch calculations. Maybe food for thought or food for a new issue.
Why are the ase potentials from pyeonclient and from within an ase_calc.py file separate anyway? Couldn't you just build an ASE potential from pyeonclient's make_potential_from_ase?

[TobiasDijkhuis]

I now realize that main is actually the branch that pull requests are merged into 🥲
Could you sync develop with main, and then merge this (after review of course), or should I close and reopen with main as a target?
Same goes for #408