How ‘Crisis on Infinite Earths,’ one of the most important comic crossover events ever, will work on TV — Avengers: Endgame and the end of the Marvel Cinematic Universe’s “Infinity Saga” may have gotten all the attention this year (and definitely earned all the money), but there’s another live-action superhero mega-event happening this December. It’s the annual crossover of The CW network’s stable of DC Comics series. The heroes…