Before Glendale-raised Nate Ruess hit it big as the lead singer of Fun — the band behind “We Are Young,” “Some Nights,” “Carry On” and many more indie-pop bops — his Valley-based band The Format was making waves locally and beyond in the 2000s. Now, 16 years since the release of their last LP, Ruess and the duo’s other half, Sam Means, are taking The Format back on tour this spring for a very limited...