Move merge request EE helper methods to `app/helpers/ee/merge_requests_helper.rb`
Basically, these methods: https://gitlab.com/rymai-gitlab/ce_ee_diffs_generator/blob/7eb249a009873896176df383d42f94eb8ab9ac7d/diffs/app-helpers.diff#L511-559
should be moved to an EE-specific app/helpers/ee/merge_requests_helper.rb
helper.