Brian Steinberg Senior TV EditorCBS News wants to spread some of its venerable newsmagazine “Sunday Morning” to other days of the week.Starting September 7, the entire CBS morning schedule will be treated as a larger franchise, with weekdays and Saturdays featuring some of the in-depth and longform features for which the Sunday show — a TV-news institution — is best known.The weekday program, which features Gayle King, Tony Dokoupil and new co-host Nate Burleson, will be retitled “CBS