```
NgLSHost: AngularLanguageServiceHost
NgLS: AngularLanguageService
```
NgLSHost should not depend on NgLS, because it introduces circular
dependency.
Instead, the `getTemplateAst` and `getTemplatAstAtPosition` methods should
be moved to NgLSHost and exposed as public methods.
This removes the circular dependency, and also removes the need for the
awkward 'setSite' method in NgLSHost.
PR Close#31122