updated several specs and factories to accomodate new permissions

As we have a central domain for auto merge process today,
we should use a single worker for any auto merge process.

Refactor

- Adds an endpoint on PipelinesController
- Adds a service that iterates over every build in a stage and
plays it.
- Includes 'play_manual' details on EntitySerializer
- Builds a new Stage state: PlayManual. An stage can take this status if
it has manual builds or an skipped, scheduled or manual status
- Includes FE modifications and specs

With Pipelines for Merge Requests feature, users cannout keep using
$CI_COMMIT_REF_NAME and _SLUG predefined variables for dynamic
environments. We fix this problem by explicitly looking at the source
ref.

This backports the changes from
https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/10452

This variable shows if the branch the runner is executing is protected
or not.
References: #50909

Backports https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/10161
(code out of ee/ folder).

This is for merge request pipelines

Adds `# frozen_string_literal: true` to spec/models ruby files

By using `refs/merge-requests/:iid/head`

ok

ok

Improve naming nicely

Add nice tests

add nice tests

fix some more

revert

For a given merge request, it's quite common to see duplicate FindCommit
Gitaly requests because the Gitaly CommitService caches the request by
the commit SHA, not by the ref name. However, most of the duplicate
requests use the ref name, so the cache is never actually used in
practice. This leads to unnecessary requests that slow performance.

This commit allows certain callers to bypass the ref name to
OID conversion in the cache. We don't do this by default because it's
possible the tip of the branch changes during the commit, which
would cause the caller to get stale data.

This commit also forces the Ci::Pipeline to use the full ref name
so that caching can work for merge requests.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/57083

This commit updates the pipeline block that appears on the merge request
page to include information that will be exposed by the API as part of
the post-merge pipeline feature.

Introduces the concept of Prerequisites for a CI build.
If a build has unmet prerequisites it will go through the
:preparing state before being made available to a runner.

There are no actual prerequisites yet, so current
behaviour is unchanged.

Introduces a new status for builds between :created and :pending
that will be used when builds require one or more prerequisite
actions to be completed before being picked up by a runner
(such as creating Kubernetes resources before deploying).

The existing :created > :pending transition is unchanged, so
only builds that require preparation will use the :preparing
status.

Make it sane

Include merge ref head

Fix union

Improve a bit

Add spec

remove

add spec

Add changelog

fix coding offence

Apply suggestion to spec/models/merge_request_spec.rb

ok

ok

Fix

Fix spec

Fix spec

fix

Simplify the things

Memoize

OK

a

fix it ok

Fix

head pipeline

Conflicts:
  doc/ci/variables/README.md
  spec/models/ci/pipeline_spec.rb

Fix

ok

Add spec

Fix

ok

Fix

Add changelog

Fix

Add memoization

a

fix

source_sha and target_sha are used for merge request pipelines

Ci::Pipeline#all_merge_requests was only returning merge requests
for that project, but it should include merge requests from forks
as well.
Signed-off-by: NRémy Coutable <remy@rymai.me>

ChatOps used to be in the Ultimate tier.

Introduce the following variables

- CI_MERGE_REQUEST_ID
- CI_MERGE_REQUEST_IID
- CI_MERGE_REQUEST_REF_PATH
- CI_MERGE_REQUEST_PROJECT_ID
- CI_MERGE_REQUEST_PROJECT_PATH
- CI_MERGE_REQUEST_PROJECT_URL
- CI_MERGE_REQUEST_TARGET_BRANCH_NAME
- CI_MERGE_REQUEST_SOURCE_PROJECT_ID
- CI_MERGE_REQUEST_SOURCE_PROJECT_PATH
- CI_MERGE_REQUEST_SOURCE_PROJECT_URL
- CI_MERGE_REQUEST_SOURCE_BRANCH_NAME

Allow to fetch all pipelines for every projects in a group and its
subgroups.
Allow to fetch the latest pipeline id for each projects of a group and
its subgroups.