API: Added comment CUD endpoints, drafted tests

Move some checks and made some tweaks to the repo to support consistency
between API and UI.

app/Activity/Controllers/CommentController.php

@@ -22,7 +22,7 @@ class CommentController extends Controller
     /**
      * Save a new comment for a Page.
      *
-     * @throws ValidationException
+     * @throws ValidationException|\Exception
      */
     public function savePageComment(Request $request, int $pageId)
     {
@@ -37,11 +37,6 @@ class CommentController extends Controller
             return response('Not found', 404);
         }
 
-        // Prevent adding comments to draft pages
-        if ($page->draft) {
-            return $this->jsonError(trans('errors.cannot_add_comment_to_draft'), 400);
-        }
-
         // Create a new comment.
         $this->checkPermission(Permission::CommentCreateAll);
         $contentRef = $input['content_ref'] ?? '';