Consider compatibility with `SciMLOperators`

[mattsignorelli]

The unification of spin and orbital makes this slightly nontrivial (SciML operators act on arrays, we have both array and quaternion) but it might be doable...

https://docs.sciml.ai/SciMLOperators/stable/interface/

[mattsignorelli]

no need for this anymore with tracking code in beamtracking.jl