instead of methods
More polish to the tag helper descriptor builders.
- Expose underlying builders as getter only list
- Added AsDictionary() extension method to BoundAttributeDescriptorBuilder
- Expose diagnostics as RazorDiagnosticCollection
- Got rid of Require** prefix in TagMatchingRuleBuilder
- Workaround issue aspnet/Razor#1492 by copying the test descriptor
extensions
This makes it possible to use another 'kind' of tag helpers, which isn't
possible today.
This also further decouples the tag helper api surface from the default
implementation.
VCTH now have their own 'kind'.
Also improved generation of display names and error messages where it
was coupled to the type name.