Abstractions - Core MVC extensibility
Controllers - MVC implementations of .Abstractions and supporting
contracts
Infrastructure - General purpose support APIs. Metadata APIs that don't
fit clearly with a feature or with .Abstraction
- #2993
- use `ClosedGenericMatcher` to handle e.g. non-generic model types implementing requested interfaces
- reduce `IsAssignableFrom()` use since created binders use explicit casts i.e. handle explicit implementations
- also add more integration tests covering various collection key formats, some with validation errors
- merge a few `[Fact]`s into `[Theory]`s
This change treats 'top-level' collection-type models similarly to
top-level POCO model - namely that they will always be instantiated even
if there's no data to put inside.
The assumption is ModelState should have entries if
1. An error is explicitly added by a model binder.
2. There is validation error reported while validating the model.
3. There is value bound by the model binder.
With this change there should be no extra entry other than for the cases mentioned above.
Also enabling the integration test cases.