There will be plenty of warmth on display as US President Donald Trump welcomes Hungarian Prime Minister Viktor Orban at the White House on November 7, but alongside the strong personal chemistry there will be a full plate of issues as they sit down to lunch. Long united by ideology and words, the two leaders are on opposite sides of the policy fence when it comes to imports of Russian oil. Meanwhile, plans for Orban to host Trump and Russian President Vladimir Putin at a summit in Budapest have been placed very much on the back burner. An exemption…