LONDON—The global economy is bouncing back strongly from the collapse it suffered in the spring, but fresh data suggest the early gains from the lifting of coronavirus lockdowns are already exhausted, adding to evidence that the world economy could take many months, if not years, to heal. Fresh figures from the U.K. provide valuable insight into the state of the continuing economic recovery. The country is one of a handful of economies to release month-to-month figures for economic growth and is also the largest to do so,…