Feature: support vf-card-container 4 column variant

`vf-card-container` now supports a 4-column layout when cards don't have images. `vf-card-container__col-4`

https://stable.visual-framework.dev/components/vf-card-container/

What is needed to have this option added to vf-wp? 

Also, I've noticed the option to style the card container header as white is not working `vf-section-header`