[autocomplete] render list of items as empty result

# Feature request

## Summary

I'm building a command palette using ``, and I would like to be able to render some default list items when there's no search results. The key point is that I still want to render the `Empty` children as a `List` with `Items` so I can keep all the interactivity.

| Default | No search results |
|------------|----------|
|  |  |

## Motivation

Maybe it's not the most popular pattern, but there are a handful of real world examples like this. For reference, here's Raycast showing a list of default results when there's no match.