By Robert O’Harrow Jr. and Shawn Boburg June 17 at 10:16 AM Follow @robertoharrow Follow @ShawnBoburg Donald Trump, left, Mayor Ed Koch, center, and Roy Cohn in 1983 at the Trump Tower opening in New York. (Sonia Moskowitz/Getty Images) Donald Trump was a brash scion of a real estate empire, a young developer anxious to leave…