git_picker: Make the unified version of it available through the title bar (#47151)

The recently-introduced unified Git picker was previously only available
if you reached for the branch, worktree or stash pickers through the
keybinding. Now, if you click on the title bar's branch button, you'll
also be able to quickly view the worktree and stash pickers.

Release Notes:

- N/A
384c8e6478Danilo Leal committed on 1/19/2026, 3:37:40 PM· committed by GitHubparentf98acf4
5 files changedLine totals unavailable