By Lucy Raitano LONDON (Reuters) -Sterling held firm on Friday and was poised to post gains for a third consecutive week, helped by better-than-expected UK retail sales numbers. Against the euro, the pound was flat at 83.39 pence. Against the greenback, it was little changed at $1.36035. Sales volumes in the UK in January rose 1.9%, surpassing forecasts of a 1.2% rise, as consumers began to return to more normal buying behaviours after a 4% drop in December 2021. “However, the key issue going forward will be whether this apparent bounce back in consumption will be able to withstand the forthco…