Also support data-pattern for Abide

[DanielRuf]

Description

Also support data-pattern for Abide.

• Closes Form validation with custom patterns fails if javascript is disabled #11671

Types of changes

• Documentation
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (anything that would change an existing functionality)
• Maintenance (refactor, code cleaning, development tools...)

Checklist

• I have read and follow the CONTRIBUTING.md document.
• The pull request title and template are correctly filled.
• The pull request targets the right branch (develop or develop-v...).
• My commits are correctly titled and contain all relevant information.
• I have updated the documentation accordingly to my changes (if relevant).
• I have added tests to cover my changes (if relevant).

[DanielRuf]

Still have to create some tests.

[kball]

I think this is reasonable as a standalone given our current state of trying to clean up old PRs and re-kickstart the project. Going to merge as is.

[joeworkman]

This pull request has been mentioned on Foundation Open Source Community. There might be relevant details there:

https://foundation.discourse.group/t/foundation-for-sites-v6-6-0-is-here-farout/30/1