Refactor discussion edit widget to have only one at a time.

Closes #23227

See merge request !8356

Removes CustomEvent polyfill and tests

See merge request !8400

Decreases font-size on login page

See merge request !8454

25701 standardize text colors

Closes #25701

See merge request !8383

Removes unneeded `window` declaration in environments related code

Closes #25725

See merge request !8456

Absorb gitlab_git

Closes #24374

See merge request !8447

UX Guide: add section on search box

See merge request !8429

UX Guide: Add new primary and secondary text colors

See merge request !8449

Explain why we have this monkey-patch

See merge request !8329

Add API route slack slash commands

Closes #25954

See merge request !8362

Removes invalid html and unneeded CSS to prevent shaking in the pipelines tab

Closes #26278

See merge request !8411

Terminal: Add TextEncoder and TextDecoder in terminal bundle.

Closes #25977

See merge request !8450

Since there are multiple instances of text editors on the current fixture file we will use the one that creates a comment.

if we are in the Merge Requests page, this change will clone existing note-edit-form and add a mr-discussion-edit-form class to cloned element so we will have two note-edit-form in place. One for Discussions tab one for Changes tab.

For MR page, we basically need two note-edit-form because you may want to edit your comment in both tabs at the same time and we shouldn't remove or discard note-edit-form in other tab.

Fix ImplicitDiv Haml lint failure

See merge request !8441

Clarify git housekeeping

See merge request !8373

Properly handle failed reCAPTCHA on user registration

See merge request !8403