“Wonka,” the new musical origin story of everyone’s favorite mischievous chocolatier, is a lot like the creative confections our protagonist conjures — we don’t need chocolate, but how can we resist such a tantalizing treat? It’s the same quandary with this movie: we never needed a musical origin story of Willy Wonka, but how can we resist this whimsical and wonderful tale crafted by “Paddington” and “Paddington 2” auteur Paul King and starring Timothée Chalamet ? Don’t even try to resist, just enjoy the indulgence. Working with “Paddington 2” writer Simon Farnaby, King puts his own stamp on t…