Framingham retail powerhouse TJX Cos. maintained discounting dominance in 2011 with soaring sales and profits, making it the Globe 100’s top consumer company for the second year in a row. Revenues at the off-price chain, which runs brands such as T.J. Maxx, Marshals, and HomeGoods, grew 6 percent to $23.2 billion, and net income jumped more than 11 percent last year. TJX made significant gains in customer traffic, luring new and existing consumers with an ever-changing assortment of designer deals.