SPRINGFIELD — Under state law, an insurance producer has an obligation in procuring coverage for his or client. But what exactly is an “insurance producer?” The state’s top court recently wrestled with that question. Ultimately, the court ruled it could describe anyone who had to be licensed to sell insurance. The result is that so-called captive agents who work directly for insurance companies — and not just brokers who act as middlemen between clients and companies — can be held …