By James Davey LONDON (Reuters) -Sainsbury’s, Britain’s second biggest supermarket group, said strong demand for premium products liked dry cured meats and steamed buns helped it to outperform the market in the key Christmas period and reiterate its annual profit outlook. The group, which has a 16% share of Britain’s grocery sector, trailing only Tesco, said it had benefited from a range of new product launches that tapped into a trend of cash-strapped consumers wanting to cook and entertain at home. Sainsbury’s, whose shares are up 24% over the last year, reported a 7.4% rise in underlying sa…