Merge branch 'dz-improve-mr-compar' into 'master'

Improve merge request versions compare logic

## What does this MR do?

Changes the way how we compare between for merge request versions 

## Are there points in the code the reviewer needs to double check?

no 

## Why was this MR needed?

So when I squash+rebase my commit I can get more accurate diff on what changed between versions

## Screenshots (if relevant)

in discussion (below)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] ~~[Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)~~
- [ ] ~~API support added~~
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/22368, https://gitlab.com/gitlab-org/gitlab-ce/issues/22721

See merge request !6589

1 files changed, 1 insertions, 0 deletions

diff --git a/CHANGELOG b/CHANGELOG
index 3b79f14076a..ab04c55b451 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -130,6 +130,7 @@ v 8.12.4
   - Fix failed project deletion when feature visibility set to private. !6688
   - Prevent claiming associated model IDs via import.
   - Set GitLab project exported file permissions to owner only
+  - Improve the way merge request versions are compared with each other
 
 v 8.12.3
   - Update Gitlab Shell to support low IO priority for storage moves