WrestleMania returns for its 38th installation in all its maximum-impact, high-volume, melodramatic, sweat-drenched, spandex-clad splendor. For entertainers, fans and marketers, pro fumbling’s biggest yearly phenomenon belongs to the Super Bowl, Coachella and television upfronts all covered into one giant display. For World Wrestling Entertainment, business entity behind all of it, WrestleMania does not simply set …