LONDON (Reuters) – Below is a summary of how Britain’s retailers fared over Christmas, after many were forced to slash prices to drive up sales in the run up to the key festive trading period. RETAILER/RIC/PERFORMANCE SECTOR Debenhams Department store Like-for-like sales up 0.1 pct in 17 weeks to December 28 Co-operative Group Food, banking Like-for-like sales up 1 pct in 13 weeks to January 4 Domino’s Pizza GroupFood Like-for-like UK sales up 10.9 pct in 13 weeks to December 29 Dunelm GroupHomewares store Like-for-like sales up 2. …