Since he introduced the world to the Cronut in 2013, Dominique Ansel has lived in a sugar-dusted universe dominated by the indulgent, cream-filled donut-croissant hybrid. At Dominique Ansel Workshop, which will open on Friday, July 16, in New York’s Flatiron District, there will be eight varieties of croissants, priced from $4.50, including one stuffed with Black forest ham and fontina …