This commit segregates interface that is require to make CI/CD entity
processable, like `Ci::Build`. With this change it is not clear and
explicit what methods need to be implement to pass an object to pipeline
processing service.

We reuse this constant in EE.

Added dropdown for diff settings

Closes #55491

See merge request gitlab-org/gitlab-ce!24460

Update merge request page object and rebase test

Closes gitlab-org/quality/staging#3

See merge request gitlab-org/gitlab-ce!24375

Upgrade webpack and monaco-editor to latest

See merge request gitlab-org/gitlab-ce!24646

Improve Target audience section for issue templates

See merge request gitlab-org/gitlab-ce!24527

Add missing attrs to Issue example API responses

See merge request gitlab-org/gitlab-ce!24641

Docs: fix typos on API page

See merge request gitlab-org/gitlab-ce!24657

Specify use of custom helm chart per env

See merge request gitlab-org/gitlab-ce!24541

Resolve "Commit comments displayed on a merge request that contains that commit no longer specify which commit they come from"

Closes #53950

See merge request gitlab-org/gitlab-ce!24427

Unified commit link in note header action text

Provide more information of release cadence

See merge request gitlab-org/gitlab-ce!24479

remove red/green colors from diff view of no-color syntax theme

See merge request gitlab-org/gitlab-ce!24582

Split project menu into separate submenus

See merge request gitlab-org/gitlab-ce!24501

Resolve "Runners IPv6 address overlaps other values"

Closes #56334

See merge request gitlab-org/gitlab-ce!24531

Document broadcast messages in UI

Closes #45801

See merge request gitlab-org/gitlab-ce!24556

Bump CI image to use Chrome 71.0 and Golang 1.11

Closes #56614 and #55578

See merge request gitlab-org/gitlab-ce!24572

https://gitlab.com/gitlab-org/quality/team-tasks/issues/84

Enable the Layout/ExtraSpacing cop

Closes #56392

See merge request gitlab-org/gitlab-ce!24423