By Brenda Goh and Min Zhang SHANGHAI/BEIJING (Reuters) -Shanghai said on Saturday it had detected no new daily COVID-19 cases outside quarantine areas, marking a milestone in its battle to contain the virus, which has paralysed the city of 25 million and put residents in the capital Beijing on edge. Streets in Beijing were eerily quiet at the start of a five-day Labour Day break, with residents anxious that authorities would impose further restrictions during a holiday when many typically travel or socialise. “You look at a city that used to be crowded and now is void. You wonder how these peo…