Since Cozen O’Connor’s lobbying arm expanded to Chicago more than a year ago, the law firm’s subsidiary has added four lobbyists to its government relations team, including John F. Dunn, Darren Collier and Patrick L. Carey earlier this month.The three new hires join Patrick G. Martin, who launched Cozen O’Connor Public Strategies’ Chicago office in July 2018, and Matthew T. Glavin, who joined in …