Also moves action buttons into the new breadcrumbs

Closes #34030, #34033

Merge branch '34097-issue-board-remove-from-board-button-when-viewing-an-issue-gives-js-error-and-fails' into 'master'

Resolve "Issue Board -> "Remove from board" button when viewing an issue gives js error and fails"

Closes #34097

See merge request !12430

Make issuable sidebar setSidebarHeight more efficient

See merge request !12252

Make entrypoint and command keys to be array of strings

See merge request !12536

Enable webpack code splitting

Closes #32989

See merge request !12032

Add issuable-list class to shared mr/issue lists to fix new responsive layout

See merge request !12591

Remove empty afterEach() from issue_show app_spec.js

See merge request !12577

Restore timeago translations in renderTimeago.

See merge request !12590

New navigation breadcrumbs

Closes #34029

See merge request !12346

Remove initTimeagoTimeout and let timeago.js update timeagos internally.

Closes #34340

See merge request !12468

Speed up issue counting for a project

Closes #33913

See merge request !12457

Automatically hide sidebar on smaller screens

See merge request !12538

Use Gitaly 0.14.0

See merge request !12586

[ci skip]

Improve support for external issue references

Closes #33679, #34076, and #34082

See merge request !12485

Remove placeholder note when award emoji slash command is applied

Closes #34470

See merge request !12545

[ci skip]

Resolve "More actions dropdown hidden by end of diff"

Closes #33861

See merge request !12380

This doesn't need to be public in CE, but EE uses it as such.

Only verifies top position after the request has finished to account for errors

See merge request !12559

This runs a slightly slower query to get the issue and MR counts in the
navigation, but caches by user type (can see all / none confidential issues) for
two minutes.

When we are filtering by a single project, and the current user has access to
see confidential issues on that project, we don't need to filter by
confidentiality at all - just as if the user were an admin.

The filter by confidentiality often picks a non-optimal query plan: for
instance, AND-ing the results of all issues in the project (a relatively small
set), and all issues in the states requested (a huge set), rather than just
starting small and winnowing further.