This MR removes most of the code for using cookies
and querystrings to set whether or not to show whitespace
diffs in merge requests.

Then saves the changes to the database directly from the
settings dropdown on the diffs page. This keeps the user preferences
in sync and makes them the single source of truth for displaying
whitespace.

Changelog: changed

Merge branch '330353-eng-experiment-update-new-user-invitation-email-test-variation-5-group-detail-and-activity' into 'master'

Experiment - Update new user invitation email with activity

See merge request gitlab-org/gitlab!63570

Revise broadcast messages docs

See merge request gitlab-org/gitlab!64088

Ignore errors related to missing interest-cohort

See merge request gitlab-org/gitlab!64057

Merge branch '332042-wiki-editor-trims-leading-and-trailing-whitespace-breaking-formatting' into 'master'

Do not trim wiki content by default

See merge request gitlab-org/gitlab!63930

Add ability to search instanceSecurityDashboard.projects GraphQL query

See merge request gitlab-org/gitlab!62933

Delete escalation policy

See merge request gitlab-org/gitlab!63774

Update CI/CD examples to use rules

See merge request gitlab-org/gitlab!63996

Update Gitaly version

See merge request gitlab-org/gitlab!64097

Migrate to Rails 6.1 connection handling

See merge request gitlab-org/gitlab!63816

Enable infrastructure registry

See merge request gitlab-org/gitlab!64072

Update Bulk Import state more accurately when import fails

See merge request gitlab-org/gitlab!63883

Update Admin Area steps in Growth docs

See merge request gitlab-org/gitlab!64087

Edit new paragraph in design doc

See merge request gitlab-org/gitlab!64085

Fix sidebar item on Jira issue details page

See merge request gitlab-org/gitlab!63954

Fix NameError Admin::ApplicationSettings::UpdateService

See merge request gitlab-org/gitlab!64055

Document how to use DAST 2.0

See merge request gitlab-org/gitlab!64054

Fix blank state styling for welcome screens

See merge request gitlab-org/gitlab!64082

Update instructions how to initialize git repository

See merge request gitlab-org/gitlab!63985

Fix: update incident sidebar severity title margin

See merge request gitlab-org/gitlab!63998

GitLab UI integration branch for 1455-flex-rename

See merge request gitlab-org/gitlab!64030

Remove cluster applications report and parser

See merge request gitlab-org/gitlab!63897

Document how to use status checks

See merge request gitlab-org/gitlab!63642

Backend support for advanced search multi-select project [RUN ALL RSPEC] [RUN AS-IF-FOSS]

See merge request gitlab-org/gitlab!62606

Allow multi select project search for Advanced Search.
Ensure single project search is supported for Basic Search.

Changelog: changed
EE: true

Change version when project access tokens were introduced

See merge request gitlab-org/gitlab!63842

Add data category to metrics definition

See merge request gitlab-org/gitlab!63856