feat: add headless workspace comment class (#7916)

* feat: add empty definitions for comment class

* feat: implement constructor

* feat: add method implementations

* feat: add own properties

* chore: add tsdoc

* fix: typos

* chore: cleanup TODOs

core/comments.ts

@@ -5,3 +5,4 @@
  */
 
 export {CommentView} from './comments/comment_view.js';
+export {WorkspaceComment} from './comments/workspace_comment.js';