Add feed-list component to Solstice Assets

In the MR for the upcoming security page redesign eclipsefdn/it/websites/eclipse.org!265, the news component used on eclipse.org's homepage, dataspaces, and orcwg has been refactored into a more re-usable and generic component.

For example, there is a bordered variant, a gapped variant where the news items are spaced out with gaps and have shadows, a horizontal list variant, a vertical list layout, etc.

This should be moved to EFSA, and the duplicate css should be removed from eclipse.org, dataspaces.eclipse.org and orcwg.org.