By William Schomberg and Andy Bruce LONDON (Reuters) -Britain’s economy grew unexpectedly in May, driven by a rise in doctor appointments but also broader demand for things such as holidays, according to data that could reassure the Bank of England about its plans to keep on raising interest rates. Economic output expanded by 0.5% in May although consumer services fell as the surge in inflation hit shoppers. A Reuters poll of economists had pointed to zero growth in May from April. Health services were a major driver of growth, the Office for National Statistics said, citing “a large rise in G…