Add stylelint rule to prevent usage of the order CSS property

[afercia]

Description

Previously:
#57519
#57640
#58936
#58940
#58942
#59013

Part of an effort to remove all the order CSS properties from the codebase.

For accessibility, visual/reading and DOM order must always match when they affect reading order and interaction. Basically thisis almost always the case. There's very limited cases where the order property can be used without affecting accessibility, for example when switching the position of an aria-hidden icon, or similare cases where the impact is only 'visual'.

To prevent future usages of the order CSS property, I'd like to propose to:

• Add a stylelint config or rule to trigger an error when an order property is found.
• In the rare cases where a stylelint-disable comment would be appropriate, require to specifi a disable reason.
• As far as I can tell, requiring a description for the disable reason in the comments is a 'global' configuration of stylelint so that will require to add a disable reason to all the stylelint-disable comments, which is a good thing anyways.

Currently, there are 2 occurrences of the order css property, here and here. They're both tracked in specific issues and they will be likely removed soon. Other occurrences have been removed already.

Step-by-step reproduction instructions

• Run npm run lint:css in yout terminal, in the project root.
• Observe stylelint doesn't report any error or warning for the usage of the order CSS property.

Screenshots, screen recording, code snippet

No response

Environment info

No response

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes