git_ui: Improve design in branch, stash, and worktree pickers (#53798)

Mainly improving label truncation as well as making date/time display
consistent between the branch and stash pickers. In the list item, we
display relative timestamps, while in the tooltip, we display it in
absolute for more details.

Release Notes:

- N/A
ea42a19531Danilo Leal committed on 4/13/2026, 4:15:00 PM· committed by GitHubparent51dffe4
3 files changedLine totals unavailable