[master] Port of: Check issue milestone availability

See merge request gitlab/gitlab-ee!857

# Conflicts:
#	ee/spec/models/burndown_spec.rb

Add project when creating milestone in specs

We validate milestone is from the same
project/parent group as issuable ->
we need to set project in specs correctly

Improve methods names and specs organization

Ensure request to link GroupSAML acount was GitLab initiated

See merge request gitlab/gitlab-ee!746

Display only information visible to current user on Milestone detail

See merge request gitlab/gitlab-ee!776

Respect group membership lock when importing a member from another group

See merge request gitlab/gitlab-ee!828

Add public/internal groups as members to your Project(IDOR)

See merge request gitlab/gitlab-ee!846

Sharing a public project with a private group makes the group page publicly accessible

See merge request gitlab/gitlab-ee!861

[ci skip]

[ci skip]

Added permissions section to issue template [EE]

See merge request gitlab-org/gitlab-ee!9729

Added permissions section to issue template [CE]

See merge request gitlab-org/gitlab-ce!25576

Update operations settings breadcrumb trail

Closes #56387

See merge request gitlab-org/gitlab-ce!25539

Update operations settings breadcrumb trail

See merge request gitlab-org/gitlab-ee!9708

Docs: fix broken OneLogin link

See merge request gitlab-org/gitlab-ee!9738

Elaborate on POSTGRES_VERSION Auto DevOps setting

See merge request gitlab-org/gitlab-ce!25579

Add documentation on upgrading GitLab HA nodes

Closes #58121

See merge request gitlab-org/gitlab-ce!25574

Fix EE master failure: project_ci_cd_settings doesn't exist Job Failed

Closes #10036

See merge request gitlab-org/gitlab-ee!9735

Merge branch '10038-environment-didn-t-match-api-schema-ee-spec-controllers-projects-environments_controller_spec-rb-job-failed-168066358' into 'master'

Add New Field `name_without_type` to API Schema

Closes #10038

See merge request gitlab-org/gitlab-ee!9728

Fix EE master failure: static-analysis: Duplicate key

Closes #10040

See merge request gitlab-org/gitlab-ee!9731

API: Promote project milestone to a group milestone

Closes #53861

See merge request gitlab-org/gitlab-ce!25203

Added: Specs for the API action

As mentioned in
https://gitlab.com/gitlab-org/gitlab-ce/issues/58121#note_145299901, it
wasn't obvious that upgrading an GitLab HA cluster required special
care. Link to the Omnibus documentation for upgrade instructions.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/58121

Remove N+1 query for tags in /admin/runners page

See merge request gitlab-org/gitlab-ce!25572

New field was added in ce, but the schema to update was hidden under the
`ee/` folder.

As discussed in https://github.com/mbleigh/acts-as-taggable-on/issues/91,
we can avoid N+1 queries if we use `tags` instead of `tag_list`.

Seen while reviewing
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/19740.