Traverse; Lyceum; Studio, EdinburghNat McCleary's new play gets to grips with Scottish identity; a French-language take on Lars von Trier glides between stage and screen; and dinner is served, big time, courtesy of actor-clown Geoff Sobelle What a light the National Theatre of Scotland has thrown on the country and its drama. In the year of its founding, 2006, the company ignited the Edinburgh festival with John Tiff…