“Anti-hate satire” Jojo Rabbit is a film that needs a bit of explaining, featuring as it does Nazis, imaginary Hitlers and Stephen Merchant as a Gestapo agent. Explaining all is Taika Waititi, the writer-director-star of the show, as well as its two younger leads, Thomasin McKenzie and Roman Griffin Davis. Even Ali has a go trying to summarise it in a few words. Well, he tries his best anyway.