HAVANA — Thousands of Cubans joined a protest Friday in front of the U.S. Embassy in Havana that was led by President Miguel Diaz-Canel and ex-leader Raul Castro against Washington’s long-standing trade blockade. “We are marching now to tell the U.S. government to let the Cuban people live in peace. Down with interference!” Diaz-Canel told a crowd that had gathered a month before Republican Donald Trump …