Kevin Hart, Dwayne Johnson and Jack Black are dispensing with all the levels. Sony Pictures unveiled a first look at “Jumanji: Open World,” the long-gestating, latest entry in the action-comedy franchise, at CinemaCon on Monday as part of its presentation to theater owners. Once again, our heroes find that the boundaries between a fantastical game and the real world have blurred. This time, the three leading actors will play three different characters. Johnson’s Dr. Bravestone, for instance, is