[BUG] Don't fire notification for comment of pending review

- When a comment was updated or deleted and was part of an
pending/ongoing review, it would have triggered a notification, such as
a webhook.
- This patch checks if the comment is part of a pending review and then
does not fire a notification and, in the case of updating a comment,
does not save the content history because this is not necessary if it is
still a "draft" comment given it is a pending comment (there is no need
to see my embarrassing typos).
- Adds integration tests.
- Resolves https://codeberg.org/forgejo/forgejo/issues/4368

models/fixtures/comment.yml

@@ -14,6 +14,7 @@
   content: "good work!"
   created_unix: 946684811
   updated_unix: 946684811
+  content_version: 1
 -
   id: 3
   type: 0 # comment
@@ -33,6 +34,7 @@
   tree_path: "README.md"
   created_unix: 946684812
   invalidated: false
+  content_version: 1
 -
   id: 5
   type: 21 # code comment