By James Davey LONDON (Reuters) – British supermarket group Sainsbury’s, seeking an edge amid a worsening cost of living crisis, will for the first time include its biggest selling lines in a scheme that matches the prices of German-owned discounter Aldi. Pessimism among Britain’s households has hit unprecedented levels as wages struggle to keep pace with inflation that reached 9% in April and is heading for double digits. To try to deter cash-strapped shoppers from switching to discounters Aldi and Lidl, Sainsbury’s, Britain’s No. 2 grocer, and market leader Tesco have schemes that match Aldi…