CE upstream: Wednesday

Conflicts:

both modified:   app/models/group.rb
both modified:   app/services/projects/create_service.rb
both modified:   app/views/projects/boards/_show.html.haml
both modified:   spec/features/issues/filtered_search/filter_issues_spec.rb
both modified:   spec/models/repository_spec.rb

More conflicts:

both modified:   app/controllers/autocomplete_controller.rb
both modified:   app/finders/issuable_finder.rb
both modified:   app/models/repository.rb
both modified:   app/views/layouts/nav/_new_admin_sidebar.html.haml
both modified:   app/views/layouts/nav/_new_group_sidebar.html.haml
both modified:   app/views/shared/issuable/_search_bar.html.haml
both modified:   config/routes.rb
both modified:   doc/README.md
both modified:   doc/api/issues.md
both modified:   doc/api/merge_requests.md
both modified:   lib/api/branches.rb
both modified:   lib/api/helpers.rb
both modified:   lib/api/tags.rb
both modified:   spec/features/issues/filtered_search/search_bar_spec.rb
both modified:   spec/fixtures/api/schemas/public_api/v4/merge_requests.json
both modified:   spec/requests/api/projects_spec.rb