Most retailers struggled through the recession. Jos. A. Bank Clothiers Inc. thrived. While other men's clothing chains were shutting stores and cutting costs in the face of shrinking profits, the Hampstead-based retailer was expanding and investing. Jos. A. Bank opened new stores — 110 nationwide since 2008, bringing the total to 527 — broadened its product line, started outlet and tuxedo-rental businesses and announced plans recently to take its e-commerce site international. Most important, throughout the downturn the company, which specializes in career wear for men, offered promotions and sharp marketing — at one point even offering to take back suits from men who had been laid off.