You envision Paris Fashion Week as a glitzy thicket of drama, and it certainly has the potential to be. Watching "Couture," we may think: Where's the editor-of-Vogue character? The international media blitzkrieg? That's the kind of hot-mess action that Robert Altman tapped into 30 years ago when he made his grandiose fashion-world satire "Prêt-à-Porter." But Alice Winocour, the French writer-director of "Couture," is having none of that. She works in a way that's deliberately defused of drama.