- #4690
- move `ModelBindingMessageProvider` init from `DefaultBindingMetadataProvider` to `DefaultModelMetadata`
- in addition to avoiding error cases, this removes some boilerplate
- add specific errors to `BodyModelBinderProvider`, `CompilerCache`, `CompositeViewEngine`, `ModelBinderFactory`,
and `ObjectResultExecutor`
- `DefaultRazorViewEngineFileProviderAccessor.FileProvider` now a `NullFileProvider` in empty case
