Seth MacFarlane created “Family Guy” when he was just a 24-year-old animator, and the hit TV show is now heading into its 18th season. MacFarlane hasn’t written for the show in nearly a decade, though, as his ambitious portfolio has grown. In this week’s “Sunday Sitdown,” Willie Geist talks to the star about his wide-ranging career, which includes hit film franchises, four Grammy nominations and a dramatic role in the new miniseries “The Loudest Voice” about the man who built Fox News.