The fraught election season of blue and red is (sort of) in the rearview mirror as bright holiday colors deck the halls and malls. Before you’re overloaded with shopping and socializing, take time out to relax and let others entertain you. From Scrooge to “SnowGirls,” symphonies to soul — and with some “Nutcracker” action hoofing it up as well — these are some of the best holiday entertainment options onstage this year.