Describe the bug
A list with required field set to true and not detected when post save

To Reproduce
Steps to reproduce the behavior. For example:

1. Have a list widget like this one:
   - { label: 'Gallery', name: 'galleryImages', widget: 'list', summary: '{{field.image}}', required: true, collapsed: false, min: 1, field: { label: Image, name: image, widget: image, required: true }, }
2. Click on Save
3. Not detecting the required field and allow to save the post

Expected behavior

When save the post and this list widget is empty should show a red border like it happens with a text field for example and not allow to save if it's empty