Add CI job to limit number of changes in MR
Some of our MR are huge. In Frontend team we split big Merge Request into smaller ones so they can be easily reviewed: https://docs.gitlab.com/ce/development/fe_guide/index.html#divide-a-big-feature-into-small-merge-requests
But there are some cases where the guidelines are not followed. To prevent this it would be great if we add a CI job that would fail if changes were bigger than 2000, for example.
This job could be allowed to fail, since in this scenario - https://docs.gitlab.com/ce/development/fe_guide/index.html#divide-a-big-feature-into-small-merge-requests - the main MR would have a lot of changes.