Childish Gambino will embark on a world tour in August four years after first releasing his “3.15.20” album, which was rereleased Sunday. The multihyphenate — better known as Donald Glover in the film and TV industry — dropped a new version of his 2020 album “3.15.20” under its original name, “Atavista,” which he called “the finished version” of his fourth …