UNITED NATIONS — Four candidates vying to lead the United Nations have spent hours being grilled about their views on issues from restoring global peace to ending escalating poverty — in what the U.N. General Assembly president called one of the toughest job interviews in the world. There was no clear victor after Chile's Michelle Bachelet, Argentina's Rafael Grossi, Costa Rica's Rebeca Grynspan and Senegal's Macky Sall fielded questions from U.N. ambassadors this past week. Plus, other