SERIES PREMIERE: Steven Soderbergh made a film called The Girlfriend Experience in 2009, and now is executive producer of this new series, which borrows the title, the basic subject and mood, and little else. The same sort of trick was attempted, and pulled off spectacularly well, with the TV itieration of Fargo, so there’s a precedent – but expecting that level of success may be unreasonably optimistic. At any rate, Riley Keough, Elvis Presley’s granddaughter, plays Christine