An employee of the biotech company at the center of the COVID-19 outbreak in Massachusetts is being criminally investigated after she defied the president’s travel ban and went to China. Of the 328 confirmed cases of the disease in Massachusetts, 30 percent of them are linked back to Cambridge-based Biogen after several employees at a conference held by the company at the Marriott Long Wharf tested positive for the virus and traveled across the country, further spreading the disease. Belmont native Jie Li is being accused of knowing she was sick and of taking medication to bring down her fever...