By Tim Kenneally LOS ANGELES (TheWrap.com) – Katherine Heigl could soon be returning to the small screen. NBC has purchased a CIA drama project that the former "Grey's Anatomy" star is attached to executive produce and star in, an individual with knowledge of the project told TheWrap on Monday. The untitled drama, which has received a put-pilot commitment will revolve around a maverick CIA officer to be played by Heigl. …