LUGANO, Swizerland — Italy’s most celebrated ballet star brought his touring gala Roberto Bolle and Friends to Lugano’s LAC Lugano Arte e Cultura this spring, drawing a sell-out crowd that had planned months ahead. With solos that test the limits of a body at its peak and a pas de deux of near-weightless grace, the evening confirmed Bolle as one of the rare performers whose name alone fills a house.