Improve rendering of JSDoc comment text with displayparts #43085

#41877 improves parsing of jsdoc comment text as well as giving the language service the option of providing display parts for comments instead of text. Currently everything is just "text" except for links. However, with small tweaks to code like getCommentDisplayParts in services/jsDoc.ts, it would be possible to format @param names as "parameterName", @template names as "typeParameterName", etc.

This could make display a lot prettier.

Note: depends on #41877 being merged.