Robyn’s 2010 electro-pop classic “Dancing On My Own” is a bit of a modern standard, a song that belongs to the world. A whole lot of people have covered “Dancing My Own” in the past decade: Kings Of Leon, Kelly Clarkson, Pentatonix. The former Britain’s Got Talent contestant Calum Scott has 450 million views on his video for his “Dancing On My Own” cover. Somehow, though, the best “Dancing On My Own” cover might not come from a professional musician. It might be the one that the entire Boston Red Sox roster sang last night.