NEW YORK (Reuters) - American alternative rock group Imagine Dragons and New Zealand singer Lorde were named Billboard Music Award finalists in 12 categories each, followed by singer Justin Timberlake with 11 and pop star Katy Perry with 10, organizers said on Wednesday. Rapper duo Macklemore & Ryan Lewis was not far behind with nods in eight categories, and will vie with Imagine Dragons, Florida Georgia Line, One Direction and OneRepublic for the top duo/group prize. ...