GeezerVison

Fixes #35524 (80% solution)

This PR makes the parser parse @link tag and the language service offer symbols for entity names found at the beginning of those tags. Links are stored redundantly with comment text, so they're only used to provide (1) a span to an editor to format in some way (2) a symbol for the declaration of the link's target.

Future PRs

1. Parse # as type-space element access: Class#method. As well as, possibly, the normal TS syntax Class["method"], which doesn't currently parse either.

Open questions

1. I parse @see {@link ...} as a @see with no reference and a link in its comment text. I think that's OK.
2. I intentionally do not parse { @link X}, with a space separating { and @. I saw this only twice in my corpus, but Andrew Casey (@amcasey) points out that it's easy to support with an additional skipWhitespace call. I originally skipped it because I had slightly less lookahead when the next token after { was @, but that made the code unreadable, so I dropped it.

Resolved questions

1. I introduced JSDocText and JSDocLink nodes into the AST, which better reflects the semantic relation of comments to their tags. It is more expensive, though, it means that jsdoc comment text is treated as a first-class member of the parse tree now.