Midtown Center, a burgeoning new development at 15th and L Streets, Northwest, has become a dining destination in recent months thanks to a wave of restaurant and bar openings. In addition to New Orleans hotspot Dauphine’s, there’s clubby Japanese dining room Shoto; Little Chicken with its big fry buckets and pitcher drinks; and three ventures from Kaimaki, a casual sister venture to Philotimo, debuts at Midtown Center.