Hide the toolbar if it has no visible items (#3654)

This PR makes the toolbar hide itself if it has no visible items.

This removes the double border beneath the tab bar when there are no
visible tools in the toolbar.

Release Notes:

- N/A

Marshall Bowers committed 2y ago

c6e44683e652decbe2de1196d583846e5e22d7a0

Parent: fd133df

Committed by GitHub <noreply@github.com> on 12/14/2023, 6:02:27 PM