This week in plot-point coincidences, there are two new pictures — “The House With a Clock in Its Walls” and “Life Itself” — in which a child is sent to live with a weird uncle after losing Mom and Dad in a car crash. One of these is a full-on horror movie, as patently unbelievable as it is genuinely terrifying, full of cheap shocks and torturous metaphysics and sporting perhaps the most annoying title of the year.