Allow getLiteralTypeFromProperty to extract name types from unions#60994

bgenia wants to merge 4 commits intomicrosoft:mainmicrosoft/TypeScript:mainfrom

bgenia:mapped-types-with-keyof-constraints-over-objects-with-union-property-names-dont-produce-membersbgenia/TypeScript:mapped-types-with-keyof-constraints-over-objects-with-union-property-names-dont-produce-membersCopy head branch name to clipboard