Better rendering for related/derived_from links

[m-mohr]

The STAC links such as related and derived_from only show a "plain" link currently although we could show a full rendering as for child and item links in some cases. Explore how that can be achieved.

• application/json => Catalog component
• application/geo+json => Item compoenent
• Mix item and child links or separate them? Where to show?
• internal vs external links, keep allowExternalAccess in mind.