The first thing to say about the largest prisoner exchange between the United States and Russia since the Cold War is thank God that’s over. The second thing to say is the story about this historic event should be about the president, his administration, foreign allies and relations, and the still-critical role of American diplomacy around the world. And that’s it. Limited to that, there’s plenty for enterprising reporters to work with – the personal and dramatic stories of each of the 16 prisoners, including a correspondent for the Wall Street Journal jailed for doing journalism and a former …