NEW YORK — An FDNY firefighter was arrested on misdemeanor assault charges after he struck a reporter with a folding chair earlier this week as a massive pro-Palestinian protest snarled traffic on the Brooklyn Bridge and other city spans, authorities said Friday. Firefighter Robert Savarese was arrested for the Monday morning assault at the foot of the Brooklyn Bridge near Park Row in Manhattan, cops and prosecutors said. The assault took place just feet from where scores of Gaza protesters paralyzed morning rush-hour traffic Monday as they blocked traffic on the Brooklyn Bridge, Manhattan Bri…