HONG KONG — A Hong Kong appeals court overturned Jimmy Lai's 2022 fraud conviction and sentencing Thursday in a rare legal victory for the pro-democracy activist. Lai, 78, a media tycoon and longtime critic of China’s ruling Communist Party, remains in prison under a 20-year sentence he received this month in a separate national security case. Though the national security case was the biggest one against Lai, he has faced multiple prosecutions that critics say are part of a broader effort to stamp out dissent in the Chinese territory, a former British colony, after mass pro-democracy protests in 2019. Lai, a British citizen, had been serving five years and nine months in jail after he was found guilty in October 2022 of violating the lease for Apple Daily, his now-defunct pro-democracy tabloid, by concealing the fact that he was operating a consulting firm on the premises.…