Closes https://github.com/zed-industries/zed/issues/19731 Adds `editor::GoToPreviousChange` and `editor::GoToNextChange` that work the same as `vim::ChangeListOlder` and `vim::ChangeListNewer` as the common logic was extracted and reused. Release Notes: - Added a way to navigate between changes with `editor::GoToPreviousChange` and `editor::GoToNextChange`