Reworks some of the existing compiler APIs to make them easier to use in a schematic and exposes a few new ones to surface information we already had. High-level list of changes:
* `getPotentialImportsFor` now requires a class reference, instead of a `PotentialDirective | PotentialPipe`.
* New `getNgModuleMetadata` method has been added to the type checker.
* New `getPipeMetadata` method has been added to the type checker.
* New `getUsedDirectives` method has been added to the type checker.
* New `getUsedPipes` method has been added to the type checker.
* The `decorator` property was exposed on the `TypeCheckableDirectiveMeta`. The property was already present at runtime, but it wasn't specified on the interface.
PR Close#48730