The 2022 death of a young Iranian woman, Mahsa Amini, after apparently wearing her hijab incorrectly and the resulting protests that rocked the country provide the new Iranian film “The Seed of the Sacred Fig” not just with its backdrop but also with its metaphorical inquiry: How can a family survive on the suppression of expression, or, in other words, on secrets and lies? It’s an incisive question given trenchant treatment by writer/director Mohammad Rasoulof, who fled Iran this year before appearing at the Cannes Film Festival in May for the movie’s world premiere.