CHICAGO — Storming an apartment complex by helicopter as families slept. Deploying chemical agents near a public school. Handcuffing a Chicago City Council member at a hospital. Activists, residents and leaders say increasingly combative tactics used by federal immigration agents are sparking violence and fueling neighborhood tensions in the nation’s third-largest city. “They are the ones that are making it a war zone,” Illinois Gov. JB Pritzker said Sunday on CNN. “They fire tear gas and smoke