prefs: allow toggling SearchEntry in the sidebar
Allow toggling SearchEntry is useful. For instance, an application may want to hide it by default when DzlPreferencesView instantiats.
Also, support getter and setter to control it.
Allow toggling SearchEntry is useful. For instance, an application may want to hide it by default when DzlPreferencesView instantiats.
Also, support getter and setter to control it.