Make the two-dimensional harmonic oscillator Hamiltonian dimensionless

[Schoyen]

As of now we give the impression that the two-dimensional HO system (and its subclasses) supports different masses, but this is not really the case as the Coulomb elements are dimensionless quantities from the article by E. Anisimovas and A. Matulis. We need to make sure that we use the same dimensionless form as in the article to avoid unnecessary errors.