Resolve "Create new component RccSelectComponent for QueryWidgets #863fw8h6r"

Naming things

The issue called for a select component, however I find the name select somewhat unclear, as there's a default html <select> element, which is actually a combobox

As such I renamed this radio-select

Roles & Multi select

The issue also mentioned optionally adding a mode property, to enable multi-select options. This however isn't allowed with radio roles. As such I'd suggest creating a new component altogether for multi selects (they should be visibly distinct in any case, so that the user can quickly tell it's multi select and not single)

A11y

See here for the required accessibility criteria of a radio group

Example usage

I pushed a second branch using the component on the homepage, to allow testing this component 236-example

Closes #236