HONG KONG — Xiao Jianhua, the Chinese Canadian billionaire and onetime trusted financier to China’s ruling elite, was sentenced to 13 years in prison on Friday, and his company fined $8 billion, after he pleaded guilty to bribery and other crimes that the authorities said had “seriously jeopardized” the country’s financial security. Mr. Xiao, whose Tomorrow Group umbrella of companies was once worth hundreds of billions of dollars, was also fined $1 million, a Shanghai court said on Friday. One of several Chinese business tycoons caught in the cross hairs…