BOSTON — Legislation aimed at tobacco and marijuana use in Massachusetts is the subject of a public hearing at the Statehouse this week.One of the bills would prohibit anyone from smoking in a car with a child in a car seat. Anyone violating the ban would face a $100 fine.Another bill would require makers of electronic cigarettes to file annual reports with the state identifying the concentration of any toxins contained in the vapor produced by an e-cigarette when used as intended by the manufacturer.The reports would be made public.