Panel search: `no results` message#100

As per discussion:
https://github.com/getkirby/ideas/issues/148

Adding a bit more info from Github to clarify what this is about:

When searching for something in the panel, I cannot see wether the search is still “working” or is done and no results were found, as both look the same.

I would expect a notification when no search results were found, something like “no results”.

@Johanna Hörrmann We’ll really try to make it before Christmas this time. Promised <3

This will be so helpful, thanks!