By Alexandria Sage PARIS (Reuters) – Leave it to Alber Elbaz, creative director of Lanvin, to pull off a Paris Fashion Week show on Thursday that retained all its elegance and class even with Kim Kardashian and Kanye West in the front row. Popcorn and champagne distracted the audience for a time before the reason for show’s delayed start became apparent: the ubiquitous Hollywood couple swooped in 40 minutes late, eliciting boos from the standing photographers. But after their tardy entrance, the focus went right back on Elbaz’s elegant creations. …