Expose the content node API to show resources / What you need

[AllanOXDi]

Overview

We will need to expose Content Node API to return "What you need metadata/requirements " section. To allow our to frontend cards component fetch and display this metadata.

[rtibbles]

Noting here, so that I don't forget - that we will also add this to the public content node endpoints (and should do so on Studio too) - but we will need to add in an empty value when fetching this from Kolibri versions that do not return this data.