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.
- Added an inner pass inside of the intermediate lowering phase to determine which directives get flowed to the final document. There were many ways to accomplish this but in order to keep the last wins mechanic for non-auto imported directives I had to let the directives get created and then removed based on if they were inherited.
- Added error case if a user attempts to import a block directive with a `FileScopedSinglyOccurring` directive usage.
- Added test cases that validate directives are properly inherited at the intermediate lowering phase.
- Updated a few tests that had incorrect assumptions.
- Left the default directive passes alone in regards to determining the "imported" directive to enable users to add their own model, inherits, etc. directives that take precedence.
- Normalized the passes in the intermediate lowering phase to handle directives identically (we don't conditionally lower anymore).
#1376
Ryan Nowak
N. Taylor Mullen