sidebar: Adjust display of workspaces in header's ellipsis menu (#54360)

This PR only displays the X icon button to close an workspace when the
number of available ones is bigger than one, and does some light UI
tweaks to how we display the project labels inside the menu item.

Release Notes:

- N/A
d7eeb5cca9Danilo Leal committed on 4/20/2026, 11:31:42 PM· committed by GitHubparentaa5293d
1 file changedLine totals unavailable