FALL RIVER — Cliff Ponte is a busy guy. He runs a local real estate group, is president of the Fall River City Council and is about to open a sandwich and coffee shop in the city. But during the past week and a half Ponte has managed, via Zoom, to tune into portions of the federal corruption trial in Boston of former Fall River mayor Jasiel F. Correia II. “I do it in between phone calls and meetings,” he said. “I multitask,” Ponte said. “I turn the volume up and down to listen.” The District of Massachusetts U.S. Attorney’s Office has charged Correia, who at age 23 in 2015 was voted in as the youngest mayor in city history, with 24 counts that include extortion, wire fraud and filing false tax returns.