Adjust to api question naming of radio and checkbox

[sliverc]

In API following types have been renamed:
RadioQuestion -> ChoiceQuestion
CheckboxQuestion -> MultipleChoiceQuestion

See projectcaluma/caluma#265 for more details also on the reasoning.

Naming of radio and checkbox in the frontend can remain as it is a layout decision the user has to be aware of

[sliverc]

@kaldras @czosel once projectcaluma/caluma#265 is merged it won't be backwards compatible and this will need to be changed.