President Trump’s former national security adviser Mike Waltz is scheduled to appear before the Senate Foreign Relations Committee next Tuesday or Wednesday for his confirmation hearing to be ambassador to the UN, Axios has learned.Why it matters: Waltz’s hearing will give Democrats an opportunity to put Trump’s foreign policy on trial and grill the former Florida congressman and Green Beret on everything from his role in Signalgate to the White House’s long-term goals on Iran and China.Trump dismissed Waltz from his position on May 1…