As part of our efforts to avoid using joins in Elasticsearch queries
&2054 we need to
"denormalize" (copy them into child docs) the permission related fields
needed for searching.

In order to allow us to search for merge requests without joining to the
project we need to store the `merge_requests_access_level` as well as
the `visibility_level` of the project on the merge request record.

This MR also introduces an extra field `project_id` for the merge
request in Elasticsearch which is redundant since we already have
`target_project_id` and `project_id` is just aliased to this value but
adding it to Elasticsearch will make the query logic simpler to share
across all document types. Previously they were all able to consistently
join to a parent "project" so it helps when changing the code they all
have a field called `project_id`.

As well as saving these new fields with the merge requests we need to
also update these fields when they change which we also do in this MR.
We need to track updates in a few places:

1. When a `ProjectFeature` record is changed (this is where
`merge_requests_access_level` lives)
2. When a `Project` is updated (this is where `visibility_level` lives)
3. When a project is moved to another group. This logic was already
implemented generically to delegate to `Project` but we update the spec
for this just to be safe.

The change to index these new fields also introduced an N+1 query which
required an update to `MergeRequestClassProxy` to preload these new fields
we're now setting in Elasticsearch.

Changelog: changed

Improve notification recipients builder db performance [RUN ALL RSPEC] [RUN AS-IF-FOSS]

See merge request !57688

Quarantine two security_reports_spec examples

See merge request !59710

Simple and optimized self_and_descendants query

See merge request !59599

Add a docs metadata check again

See merge request !59228

Add SAST documentation on SELinux support

See merge request !59411

Fix flaky spec in spec/models/packages/debian/group_distribution_spec.rb

See merge request !59708

The array elements can be returned in any order, so just check for that.

Failing due to known bugs
QA failures #297164
#299975
#328035

Follow up to initial MR

See merge request !59574

Refactor and update MWPS e2e test after CR

See merge request !59440

Merge branch 'philipcunningham-add-backend-for-specifying-target-type-for-on-demand-294060' into 'master'

Add backend support for specifying target type [RUN ALL RSPEC] [RUN AS-IF-FOSS]

See merge request gitlab-org/gitlab!58723

Step 2 - Add docs for "Reject unsigned commits" caveats

See merge request !58465

Add valid values for cadence

See merge request !59621

Tidy up this small section to better meet GitLab tone and style.

Resolve "Style/ParallelAssignment rubocop failure"

See merge request !59688

Update Gitaly version

See merge request !59657

Revise expectation on explicit coordination in feature flag rollout template

See merge request gitlab-org/gitlab!59633

Update dependency core-js to ^3.10.2

See merge request !59683

Clarify that VSA only includes items that have reached the end event

See merge request !58707

Allow filtering alertManagementIntegrations GraphQL by ID [RUN ALL RSPEC] [RUN AS-IF-FOSS]

See merge request !57590

Externalize strings in file _confirmation_instructions_account.text.erb

See merge request !58215

Support multiple columns in column copy triggers

See merge request !58177

Merge branch '326053-clarify-that-a-stage-has-to-be-added-to-run-dast-in-gitlab-ci-yml' into 'master'

Clarify that a stage has to be added to run DAST in .gitlab-ci.yml

See merge request !59496

OKR: Update external wiki UI text and docs

See merge request !58600

Fix for transient discussion e2e spec

See merge request !59497

Externalize strings in instance_configuration/_gitlab_pages.html.haml

See merge request !58437