Support fieldset CSS for Drupal 10.4+

@yas Please review this patch. This takes care of a few things

1. Fixes the white background because in Drupal 10.4+, the css class is accordion and not card anymore
2. Changes all double quotes to single quote because of Drupal coding standards reported by prettier
3. Moves css attributes around reported by prettier. For example, all transition attributes need to be moved lower in a css class
4. Setup Grunt so it automatically runs a local prettier to reformat all code based on the .prettierrc.json

@baldwinlouie

Thank you for the great patch. I confirmed it fixed the issue. I’ll merge the patch to 5.x and 6.x; and close this issue as Fixed.

Automatically closed - issue fixed for 2 weeks with no activity.