[BUG] Rendering of radios, checkboxes and select, if no option is given

[mschwemer]

If there is no option given for checkboxes, radiobuttons and selects, one element is rendered and can be selected.

Possible future behaviour is not to render the element, just show a label.

Maybe there will be an issue, if this field is set as mandatory in the form configuration.

Followup of #999