“Sing 2” proves to be a delightful continuation of the initial "Sing" from 2016, standing out as one of those uncommon sequels that actually manages to improve upon what came before. The story picks up with Buster Moon (Matthew McConaughey) and his group celebrating sold-out performances at their theater. However, content with local success isn't enough for Buster; he and the team decide to head to a major city to…