Custom Action support

See merge request gitlab-org/gitlab-ce!21034

Port changes for CODEOWNERS to CE

See merge request gitlab-org/gitlab-ce!21309

Enable Kubernetes RBAC for GitLab Managed Apps for existing clusters

See merge request gitlab-org/gitlab-ce!21127

Fix usage statistics typo documentation

See merge request gitlab-org/gitlab-ce!21555

Resolve "Update presentation for SSO providers on log in page"

Closes #44943

See merge request gitlab-org/gitlab-ce!21233

Explicit hashed path check for trace, prevents background migration from…

See merge request gitlab-org/gitlab-ce!21533

- Use proper HTTP codes for /api/v4/allowed response
- CustomAction support

- if #check_custom_action!(cmd) returns something, return from #check()
- now returns :Gitlab::GitAccessResult::Success.new instead of true

Add User-Agent to production_json.log

See merge request gitlab-org/gitlab-ce!21546

Update user markdown documentation for CommonMark

See merge request gitlab-org/gitlab-ce!21509

Enable CommonMark for files and wikis

See merge request gitlab-org/gitlab-ce!21228

Fix LineBreakAroundConditionalBlock cop for a conditional after rescue

See merge request gitlab-org/gitlab-ce!21535

Resolve "Improve project overview UI"

Closes #44704

See merge request gitlab-org/gitlab-ce!20536

This ports the changes for the CODEOWNERS feature to CE:
- It adds the CODEOWNERS file.
- It adds the mention of the `with-codeowners` branch in TestEnv

Upgraded Monaco editor version

See merge request gitlab-org/gitlab-ce!21526

CE backport of changes that introduce custom instance-level templates to EE

See merge request gitlab-org/gitlab-ce!21530

Bump browser gem to v2.5.3

See merge request gitlab-org/gitlab-ce!21547

Full list of changes: https://github.com/fnando/browser/blob/master/CHANGELOG.md

This will help production gain more visibility which browsers may be
having issues.

Add route information to lograge structured logging for API logs

Closes #50993

See merge request gitlab-org/gitlab-ce!21487

Fix documentation on upgrading when using a Helm chart

See merge request gitlab-org/gitlab-ce!21539

Add support for advanced CI/CD config extension with `extends:`

Closes gitlab-ee#6136

See merge request gitlab-org/gitlab-ce!21243

Fix multipart error on rails reload

See merge request gitlab-org/gitlab-ce!21540

remove comma

See merge request gitlab-org/gitlab-ce!21536

Merge branch '45938-postgres-timeout-when-counting-number-of-ci-builds-for-usage-ping' into 'master'

Resolve "Postgres timeout when counting number of CI builds for usage ping"

Closes #45938

See merge request gitlab-org/gitlab-ce!21523

Document that when updating using a Helm chart 'helm repo update' needs to be run before the 'helm upgrade ...' command.  

then each commit or push triggers your CI pipeline. 

Remove unnecessary logic from group labels page

See merge request gitlab-org/gitlab-ce!21518

Previously this would violate on the `if`:

    def a_method
      do_something
    rescue
      if condition
        do_something
      end
    end