Series can have unreliable narrators, “Money Heist,” for example. But what about unreliable heroes? Just cast in a lead role in “Dexter Resurrection” Season 2, Dan Stevens delivers one, playing Pepper in AMC ’s “ The Terror: Devil in Silver ,” executive produced by Ridley Scott at Scott Free and celebrating its world premiere at Canneseries April 27. Pepper is first seen teaching his girlfriend’s young daughter how to play drums. He has plans, he tells his girlfriend, to teach other kids in the