By Arielle ApplebyDoors to the stately brick-walled SoWa Power Station opened to a maze of contemporary art booths on a nippy Thursday night in October. The smell of fresh paint lingered, ambient jazz cushioned a buzz of voices and laughter, while the signature sound of cocktail shakers prepped drinks for an edgy young crowd. Many members of Boston’s new generation say they are hungry for art, and perhaps for the first time, their appetite was satiated at the Affordable Art Fair held