SINGAPORE — Beyond China’s ostentatious display of its J-35A fighter jet at the Singapore Airshow was a lower-profile piece of equipment, the new Wing-Loong X combat drone, which experts say is far more likely to find international success. Beijing banked on Asia’s largest aerospace event, organized here from Feb. 3-7, to flex its aviation muscle, in a bid to attract more customers. At the enormous booth of the country’s top aerospace manufacturer, Aviation Industry Corporation of China, or