Component: Standardize on Attributes

Should (and can) the type property be more flexible to allow passing in simple arrays of attributes? The template will support it but I'm not sure how that affects validation.

Something like...

props:
  type: object
  properties:
    attributes:
      type: ['Drupal\Core\Template\Attribute', 'object', 'null']
      title: Attributes
      description: Wrapper attributes.

I encountered issues with Drupal\Core\Template\Attribute and SDC Display, in particular. When including an Attribute, the component display form would not render. See 🐛 Drupal attribute properties break form generator Active for details.

Even though the issue is closed as a duplicate there, the actual issue fix is on the schema-forms-php package and seems different. There wasn't a PR available there the last time I was setting up components, so this may resolve the issue I was experiencing.

This has been merged in and will be included in the next tagged release.