Add methods to help with periodicity

[EmilyBourne]

E.g.
https://github.com/gyselax/gyselalibxx/blob/5c9d12ca78ca0a18a924dbf90906b120ea582d8d/src/utils/ddc_helper.hpp#L67-L91

or other methods to place a point (DiscreteElement/Coordinate/DiscreteStep) back inside a domain