LONDON (Reuters) - Lidl GB said its total sales rose 11% in the four weeks to Dec. 29 as the British arm of the German discount supermarket group outshone bigger rivals in what was otherwise a subdued Christmas period.The company, the UK's seventh biggest grocery chain with a market share of 6%, said on Friday that strong sales of beers, wines and spirits as well as higher demand for general merchandise boosted its performance.Britain's big four supermarkets - market leader Tesco , Sainsbury's ,..