Unit tests: Checkboxradio: Ensure widget correctly handles dynamic instantiation of its parent controlgroup as well as manual value changes.
Controlgroup: Refresh after chaining up, because checkboxradio needs to see the updated options to style itself correctly.
Checkboxradio: Widget behaves correctly inside controlgroups as they are dynamically instantiated and as their type is toggled at runtime and refreshes correctly after manual value change followed by refresh. Fixes #6437.