Resolve "Create RccPullDownComponent #37hg3wd #861m549y1"

Testing

Because this component isn't yet visible, I created an example branch, showing the component on the homepage, with example options, you can find it at 241-example

A11y

The accessibility requirements of such a component are somewhat specific. Normally I'd say it's better to use the default html <select> element, however implementing the desired design with this would have been tricky (the rollout effect, for example, I'm not sure how one would have achieved this).

So instead this merge request is using the (combobox pattern)[https://www.w3.org/WAI/ARIA/apg/patterns/combobox/]. This pattern is somewhat broadly defined. Specifically we're using the single-select style combobox, with a listbox as it's popup element.

This means that text input is only optional. For now I've not implemented any text input, as I heard from Christian that there were some plans from the design side to have this being a editable style combobox.

Closes #241 (closed)