When creating a new thread on a merge request by using the [MR Discussions
API](https://docs.gitlab.com/ee/api/discussions.html#create-new-merge-request-thread),
the thread is always on the merge request's full diff.

This patch allows passing the "commit_id" parameter to associate the thread
with the desired commit.  Additionally, the "commit_id" field of a note
is exposed if the note is a diff note on a merge request.

Use case: for merge requests with many commits, I like to add my threads
on individual commits, so reviewers can immediately find the commit that
introduced the discussed lines.  This can be done in the web interface by
commenting on the diff of a commit within a merge request.  This commit
allows to do the same thing using the API.

Fix job trace polling bug

See merge request gitlab-org/gitlab!48516

Only start trace polling
when the job has started
and has a trace. Do not
poll if page is not visible.

Clean last round of warnings in the style guide

See merge request gitlab-org/gitlab!49154

More tinkering, and some judicious Vale disabling, to bring the
style guide page closer to GitLab tone and style.

Fix trailing spaces in the gitlab repository

See merge request gitlab-org/gitlab!49165

Refactor container registry list page to grapqhl

See merge request gitlab-org/gitlab!48602

- queries
- mutations
- fragments

Add link to Go linter plugins subgroup

See merge request gitlab-org/gitlab!35216

Global Search - Searchable Dropdown

See merge request gitlab-org/gitlab!48186

This creates a generic
searchable dropdown
for the Group and
Project Filters on
the Global Search.

This will both clean up
duplicated code as well
as keep them both aligned
in style moving forward.

The variable INDEX_NAME was missing.

See merge request gitlab-org/gitlab!49077

Refactor webhook docs

See merge request gitlab-org/gitlab!49090

Update feature flag section of PrAT docs -- cherry pick

See merge request gitlab-org/gitlab!48786

Implement Clone quick_action

See merge request gitlab-org/gitlab!48394

Add experiment record context

See merge request gitlab-org/gitlab!48896

Remove feature_flags_new_version feature flag

See merge request gitlab-org/gitlab!48442

Expose upcoming deployment in environment.json

See merge request gitlab-org/gitlab!48449

Remove avg_cycle_analytics from usage ping

See merge request gitlab-org/gitlab!47812

Create remediation entries while storing reports in database

See merge request gitlab-org/gitlab!48618

Remove fa- instances from js specs

See merge request gitlab-org/gitlab!49114

Refactor site validation modal component

See merge request gitlab-org/gitlab!48017

Remove suggested approvers

See merge request gitlab-org/gitlab!49016

We will start using only the remediation entries after migrating the
existing findings.

Add primary key to elasticsearch_indexed_projects

See merge request gitlab-org/gitlab!48919

Update dependency @gitlab/svgs to v1.176.0

See merge request gitlab-org/gitlab!49159

Prometheus integration name should not have a modifiable input field

See merge request gitlab-org/gitlab!48437

Monthly fix of files containing trailing spaces in the gitlab
repository.

Removes preload of fontawesome font

See merge request gitlab-org/gitlab!49156

Add git read namespace onboarding action

See merge request gitlab-org/gitlab!49007

Add `project_settings` to high-traffic tables list

See merge request gitlab-org/gitlab!49155

Add a top level notification dot for what's new

See merge request gitlab-org/gitlab!48416

Override WORKHORSE_URL to check security mirror

See merge request gitlab-org/gitlab!49139

Added EC2 to ADO docs

See merge request gitlab-org/gitlab!48721

Merge branch '277130-add-a-new-column-called-finding_uuid-into-the-vulnerability_feedback-table' into 'master'

Add new column `finding_uuid` into `vulnerability_feedback` table

See merge request gitlab-org/gitlab!48923

Includes migration, changelog and schema