Actress Sophia Lillis from the recent “It” films, moves from dealing with a scary clown to encountering a scary witch in the horror fantasy, “Gretel & Hansel,” based on the classic Brothers Grimm story. Gretel leads her little brother into the dark forest in search of sustenance only to meet up with a wretched enchantress, played by Alice Krige, best known as the diabolical Borg queen from the Star Trek franchise. Are you suffering from insomnia? Try ”Gretel & Hansel.” It’s the cinematic equivalent of Ambien but requires no prescription.   For something a bit more lively, try Blake Lively. She, Jude Law and Sterling K. Brown lead an impressive cast in the action drama, “The Rhythm Section,” based on Mark Burnell’s novel. Lively plays a woman who tries to uncover the dark truth behind an airplane crash that resulted in the death of her family members. When it becomes clear that the crash was intentional, she sets out on a dangerous mission to find the culprits. Oh, and Law trains her to be an assassin. All of the shaky camera work in the world can’t make this story seem realistic.   Also opening this week, “Taylor Swift: Miss Americana”…