John Hopewell Chief International Correspondent Is this now an age of TV caution? A brace of big swings at this week’s London TV Screenings belie that trend, and few come bigger than the English-language action thriller “Paris Has Fallen,” which Studiocanal launches at this week’s London TV Screenings. Like other major LTVS plays, it takes a mainstream genre – such as, elsewhere, the historical drama (“Wolf Hall: The Mirror and the Light”), true crime (“A Cruel Love: The Ruth Ellis Story”) and the bio (“So Long, Marianne”) – and aims to elevate them to another level.