The Orchestre de l’Opéra Royal led by violinist Théotime Langlois de Swarte offer a unique survey of the music of Joseph Bologne, Chevalier de Saint-Georges, drawn from varied performance contexts:  sonatas for piano and violin, string quartets, concertos, opéras-comiques, concert arias, and symphonies. “His music — that of a performer-composer, as it was the case for most musicians of the …