LONDON—Britain has received far more applications for visas from Hong Kong than from the European Union after a new system opened up for residents in the former British colony and post-Brexit rules kicked in, a report said on Thursday. There were 34,000 applications from Hong Kong residents to live in Britain in the first three months of the year compared to 5,354 for any type of visa from those in the EU, the Migration Observatory at the University of Oxford said. Hong Kong returned to China in 1997 with the promise of continued freedoms not enjoyed on the mainland, including freedom of expression and an independent legal system. The influx of Hong Kong applications comes after Britain announced a new scheme from Jan. 31, allowing residents to apply for a visa and the chance to become British citizens after Beijing’s imposition of a national security law last year, clamping down …