Now that the Angular LS is a proper tsserver plugin, it does not make
sense for it to maintain its own language service API.
This is part one of the effort to remove our custom LanguageService
interface.
This interface is cumbersome because we have to do two transformations:
ng def -> ts def -> lsp definition
The TS LS interface is more comprehensive, so this allows the Angular LS
to return more information.
PR Close#31972
This PR adds the implementation for `definitionAndBoundSpan` because
it's now preferred over `definition`. vscode would send this new request
for `Go to definition`. As part of this PR the implementation for
`definition` is refactored and simplified. Goldens for both methods are
checked in.
PR Close#30125
Keen Yee Liau