Document ChatOps for actor feature gates

See merge request gitlab-org/gitlab-ce!25815

Quarantine CI variable support spec

See merge request gitlab-org/gitlab-ee!9882

Quarantine failing ssh key test

See merge request gitlab-org/gitlab-ce!25813

Quarantine: Update failure issue link

See merge request gitlab-org/gitlab-ce!25811

The documentations only covered the percentage based feature gates.
These don't work really well for a number of reasons, for example; a new
visual element in GitLab would be weird to see only 25% of the time.

Allowing feature gates based on projects and groups has been supported,
now it's documented.

CE backport of ee-parallel-diff-view

See merge request gitlab-org/gitlab-ce!25734

Fix EE differences in parallel_diff_view.vue

Closes #10007

See merge request gitlab-org/gitlab-ee!9825

Re-add gitlab:ui:visual ci job

Closes gitlab-ui#192

See merge request gitlab-org/gitlab-ce!25808

Making review-performance run on master in scheduled runs

Closes #57881

See merge request gitlab-org/gitlab-ce!25757

PUT MergeRequest API endpoint - accept labels as an array

See merge request gitlab-org/gitlab-ce!19914

Expose merge request entity for pipelines

See merge request gitlab-org/gitlab-ce!25679

Resolve "Introduce zoom and scroll functionality on metrics charts"

Closes #57085

See merge request gitlab-org/gitlab-ce!25388

Adds the ability to change data zoom for metrics graphs

Resolve "Limit Group Security Dashboard to selected types of vulnerabilities"

Closes #9393

See merge request gitlab-org/gitlab-ee!9626

Allow protected branch creation via web and API

Closes #53361

See merge request gitlab-org/gitlab-ce!24969

This commit includes changes to add `UserAccess#can_create_branch?`
which will check whether the user is allowed to create a branch even
if it matches a protected branch.

This is used in `Gitlab::Checks::BranchCheck` when the branch name
matches a protected branch.

A `push_to_create_protected_branch` ability in `ProjectPolicy` has been
added to allow Developers and above to create protected branches.

Use optional encryption strategy for Runners Tokens

Closes #54859

See merge request gitlab-org/gitlab-ce!25532

This makes code to support encrypted runner tokens.
This code also finished previously started encryption
process.

EE: Use optional encryption strategy for Runners Tokens

See merge request gitlab-org/gitlab-ee!9841

Fix object storage link in doc

See merge request gitlab-org/gitlab-ce!25791

CE FE Add PersistentUserCallout factory method

See merge request gitlab-org/gitlab-ce!25481

Resolve "Add Saturday to Localization first day of the week"

Closes #58023

See merge request gitlab-org/gitlab-ce!25509

EE Port: Add Saturday to first day of the week

Closes gitlab-ce#58023

See merge request gitlab-org/gitlab-ee!9797

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/58023

- docs for adding Saturday for first day of the week
- add related settings for Saturday as first day of the week
- firstDayOfWeek: Use enumeration, replace day's numbers with
  corresponding names
- make some variables lowercase (follow camelCase)
- add CHANGELOG entry

Author:    haghighi_ahmad <haghighi.ahmad@gmail.com>