Student activists inspired by the students of Parkland, Fla., and the March for Our Lives rally organized a town hall yesterday afternoon to question leaders on gun violence and prevention.U.S. Reps. Michael E. Capuano and Stephen F. Lynch were among state legislators and city councilors in Roxbury who took part in a “Town Hall for Our Lives.” Similar events were held state- and nationwide.Capuano said the state has done more than pretty much anybody on gun legislation, but it could always do more.