RFC: Add Geoportal NRW as the pimary source for some datasets we already harvest via open.nrw.

While filtering for the topic category "environment" via the CSW filter language was straightforward, I was unable to produce a landing page as metadatasets are apparently displayed only via map.apps. (They use SmartFinder to edit the metadata but hide even the viewer behind a mandatory login.)

Due to the missing landing page, I am unsure whether we should add this as a primary source?