Function add_folder_row 

pub(super) fn add_folder_row(
    list: &ListBox,
    entry: &WatchPathEntry,
    fallback_catchup_mode: StartupCatchupMode,
    albums_ref: Rc<RefCell<Vec<(String, String)>>>,
    tracked_rows: &Rc<RefCell<Vec<FolderRowData>>>,
    on_settings_changed: Rc<dyn Fn()>,
)

Append a new watched folder row to the settings folders ListBox.