An ex-top state aide who lived a life of luxury allegedly fueled by millions of dollars in kickbacks from China is headed to trial — and the case could expose a brazen Beijing influence campaign in the highest reaches of Albany. In exchange for advancing China’s agenda in the Empire State, Linda Sun and her husband, Chris Hu, were showered with payoffs — which they used to splurge on a gaudy $4 million Long Island mansion, a $2 million second home in Hawaii and flashy cars like a Ferrari Roma,