After #33, implement the properties of `ElectricMultipoleParameters` similar as we d for the `MagneticMultipoleParameters`. https://pals-project.readthedocs.io/en/latest/element-parameters.html#electricmultipolep-electric-multipole-parameters
After #33, implement the properties of
ElectricMultipoleParameterssimilar as we d for theMagneticMultipoleParameters.https://pals-project.readthedocs.io/en/latest/element-parameters.html#electricmultipolep-electric-multipole-parameters