Persist order of draft comments added
## Context
The following discussion from !51718 should be addressed:
- [ ] @pslaughter started a [discussion](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/51718#note_514878783): (+1 comment)
> **issue (ux,non-blocking):** Just noticed that the order of draft notes isn't persisted?
>
> | Initial | Then, Change Sort | Then, Refresh page | Then, Change Sort |
> |---------|--------------|--------------|--------------|
> |  |  |  |  |
>
> This probably isn't a blocker. We should probably create a follow-up issue for it.
>
> FWIW, the data-driven suggestion + exposing `created_at` in the BE would probably immediately fix this.
>
> /cc @pedroms
/cc @leetickett @pedroms
issue