Is it a #MeToo-era revenge thriller? A 21st-century “Fatal Attraction”? A candy-colored feminist polemic, to strains of Paris Hilton and Britney Spears? A black comedy? A comic tragedy?None of the above — and all of the above. Which is to say: a film as bracingly original as Emerald Fennell’s “Promising Young Woman" defies labels.Here’s a couple good adjectives, though: Startling — the only way to describe Fennell’s vision and execution in this, her directorial debut.