BRUSSELS — Online marketplace Shein is rolling out an age-assurance tool to keep underage users away from inappropriate products, the company’s lawyer told lawmakers on Tuesday. The move follows outrage and regulatory pressure on the platform over the sale of sex dolls in November. The EU executive had demanded information from Shein on how it checks users’ age to make sure they cannot see inappropriate products. Shein has deployed a “third-party solution” on its website that is being rolled