The original intent of the labelString was that it would enforce a single line for the select box. Having a different component for the pseudo-select (button) and the pseudo-option (div) complicates things, though. If we must enforce single-lined-ness, we can do so with a non-wrapping flexbox, but we should be able to evaluate from the various callsites whether that's needed or not.

This will require going through a few locations in the app where we use it and making sure there aren't unintended consequences, but we can simplify how we're handling our listboxes.