message: fix(language-service): expose `package.json` for vscode extension resolution
  The VSCode extension looks for `@angular/language-service/package.json`
  using `require`. This currently breaks as of the ESM changes because
  we introduced the `exports` field but did not expose the `package.json`.
  This commit fixes it.
  PR Close
diff: "types": "./index.d.ts",
  "default": "./index.js"
  },
  + "./package.json": {
  + "default": "./package.json"
  + },
  "./api": {
  "types": "./api.d.ts",
  "default": "./api_bundle.js"
  