AUGUSTA — The graduation ceremony was like any other: black caps and gowns and general advice doled out, with students told they have bright futures ahead of them. But the four students who received their high school diplomas at a small ceremony Tuesday had never sat in classrooms with their fellow graduates or even met them in person before that day. The students, along with a fifth who couldn’t attend the ceremony, were the inaugural graduates of the state’s first virtual charter school, Maine Connections Academy. This past school year, four years after Maine lawmakers approved the law allowing charter schools, there were six charter schools in the state, but Maine Connections Academy was the only one without physical classrooms.