BOSTON — Legislation that would allow firearms to be taken from people who show unstable or potentially dangerous behavior is moving forward at the Massachusetts Statehouse. The House Ways and Means Committee approved the so-called red flag bill on Monday by a 24-2 vote. The measure is scheduled for debate by the full House on Wednesday. Under the proposal, family members could petition a court for an extreme risk protection order if they believe a legal gun owner poses a risk to themselves or others.