Made interference function strategies independent of scalar/matrix formalism; this now enables all strategies to be used with polarization

Refactor: changed evaluate interface of interference functions and form factors to use angle bins instead of only angles

Added required interfaces and preliminary implementation for magnetic calculations in IInterferenceFunctionStrategy classes and DecoratedLayerDWBASimulation

- 3rd person form: "Does" this or that.
- For all const methods that return something: "Returns" ...
- For boolean return value: "Returns true if " ...

manual editing of @brief ("defines ...", "implements ..."), removed multiple white lines

Moved implementation of Hann function to strategy class and implemented the scattering intensity calculation