By Mickey Rapkin By Mickey Rapkin I’m not sure when I first heard of Cameo. You know, the app that lets you buy personalized greetings from celebrities for your friends, family and even your enemies. But it was suddenly everywhere, the kind of pop culture talking point that gets name checked on two different SNL sketches in the same night. Season two of Netflix’s docuseries Cheer, whichdropped earlier this year, opened with a montage of its cast members fulfilling a seemingly endless flood of Cameo requests. To be clear, these were cheerleaders at a community college in rural Texas. And some o…