BRUSSELS (AP) — The European Union’s former foreign policy chief resigned on Thursday as head of a prestigious institute of European studies after becoming embroiled in a fraud investigation over a training program for junior diplomats. Federica Mogherini said she was stepping down as Rector of the College of Europe, based in the Belgian city of Bruges, and as of the European Union Diplomatic Academy. Mogherini’s statement gave no reason for the resignation, saying only that she had done so “in