A DIRECTV informational slate on a dropped television channel. (Photo by Matthew Keys for The Desk) If you’ve ever turned on the big game, or the local news, and found a blank screen with a “dispute” notice, you’ve run into retransmission consent. It’s one of the least-understood corners of the TV business, and it affects how much you pay for TV and whether you can watch your local stations. Here’s how it works. What is retransmission consent? R…