Issue #2665992 by alexpott, klausi, heykarthikwithu, xjm, tstoeckler: @file is not required for classes, interfaces and traits

Issue #2195573 by Xano, eiriksm, heddn, ParisLiakos, Les Lim, Pere Orga, dinarcon, xjm, alexpott: Add a dedicated @LanguageNegotiation annotation class