The characters that Amy Sedaris has created in her more than two decades in show business are distinctive, strange … and hilarious. Think Jerri Blank in “Strangers With Candy” or even, well, Amy Sedaris in “At Home With Amy Sedaris.” On Saturday, she’ll be the first woman to earn the Ernie Kovacs Award from Dallas VideoFest. Ahead of her trip to town, she talked with Krys Boyd, on a recent episode of “Think,” in which they discussed how she’s been developing these characters since she was in elementary school.