So that’s what’s happened to all our lost socks! On Friday night at New York Fashion Week, Toni Braxton helped unveil a custom dress made entirely of socks, designed byProject Runway All Stars’ Michael Costello. The gown is the centerpiece of the “SheKnows Where the Other Sock Went” campaign, an initiative fromSheKnows.com to raise money for charity. “When SheKnows called me … I was all over it,”…