Scarlett Johansson will host Saturday Night Live March 11, scoring a fifth time in the spot. The episode’s musical guest will be Lorde, making her debut solo performance on the show. Johansson’s episode follows the previously announced March 4 episode with Octavia Spencer and musical guest Father John Misty. Johansson will be promoting her new movie Ghost in the Shell, hitting theaters March 31. Her previous SNL hosting gigs were January 14, 2006; April 21, 2007; November…