(during all of this week, Screen Comment’s Eric Althoff gives readers his take on the choicest films from the 2020 crop of AFI Docs, the world’s premier documentary film festival which took place online this year due to the coronavirus). He was one of the most famous fixers of the last century, who rubbed elbows with everyone from Joseph McCarthy to then-real estate tycoon Donald Trump.  But Roy Cohn, the pugnacious New York attorney who took on