This makes it a lot easier to work on background indexing because you can easily see how background indexing is making progress.
Resolves#1257
rdar://127474057
The naming was quite inconsistent here. Let’s rename these to `LanguageService` to highlight that they belong together.
- ToolchainLanguageServer -> LanguageService
- SwiftLanguageServer -> SwiftLanguageService
- ClangLanguageServerShim -> ClangLanguageService