UX: Allow select-kit to have an autofocus option (PR #12183)

On some modals the main/primary input field is a select-kit component (like {{email-group-user-chooser}} on the assign modal), so it makes sense to allow select-kit to steal focus on modals like these. This PR adds an autofocus option (default false) that allows select-kit to steal focus when it’s rendered.


LGTM, let’s try this and see if weird cases arise