Kenneth Branagh’s latest Agatha Christie takes his drag king rendition of Hercule Poirot to drippy, trippy post-war Venice. Poirot, reticent and retired, dodges potential clients and has pastries hand-delivered to his fashionable palazzo by gondola, all while being fawned over, I mean protected, by a handsome Italian tough (Riccardo Scamarcio). But alas, his 1989-style hermitage…