By Saeed Azhar, Sinead Cruise and Selena Li NEW YORK/LONDON/HONG KONG (Reuters) -Goldman Sachs began laying off staff on Wednesday in a sweeping cost-cutting drive, with around a third of those affected coming from the investment banking and global markets division, a source familiar with the matter said. The long-expected jobs cull at the Wall Street titan is expected to represent the biggest contraction in headcount since the financial crisis. It is likely to affect most of the bank’s major divisions, with its investment banking arm facing the deepest cuts, a source told Reuters this month. …