TORONTO — Collision is back in Toronto after two years of virtual conferences, and the industry is taking full advantage of the thousands of entrepreneurs, investors and executives together in one venue. In one corner of the buzzing exhibition hall, two entrepreneurs pitched a mental-health startup before an audience of about 100 people. In another, a large TV screen showed a real-time map of where RBC customers spend money with credit cards, part of an exhibition where Canada’s largest bank was showing off its tech bonafides.