WHEN this decade began, Alexa was still just a girl’s name and few even knew the name Meghan Markle. In a special series, our experts reflect on the changing trends of the past ten years. Showbiz REALITY TV stars literally took over the world in the past decade – and the course of entertainment and politics changed with it for ever. Imagine just ten years ago thinking about the host of the US version of The Apprentice, Donald Trump, sitting in the Oval Office as America’s president with two informal advisers — controversial rapper Kanye West and his reality TV star wife Kim Kardashian. Nope, me neither. But it is proof that showbiz drives our culture more than ever as we head into 2020. Closer to home, that was summed up when American actress Meghan Markle — then a relatively unknown star of minor-league TV drama Suits — became one of the most famous women on the planet after marrying Prince Harry.In terms of love it was also the decade that saw George Clooney finally tie the knot, while the world’s most loved couple, Brad Pitt and Angelina Jolie — aka Brangelina — split. Gwyneth Paltrow and Chris Martin didn’t…