Themes-pages should list all datasets with the respective data-theme

[schiersner]

Describe the solution you'd like

The theme-page (https://datenadler.de/kategorien) lists all themes according to DCAT-AP.de. When opening a theme-page (e.g. HEAL) all datasets referencing to the same theme (e.g. http://publications.europa.eu/resource/authority/data-theme/HEAL) should be listed. So far, only manually entered datasets are listed here (e.g. https://datenadler.de/kategorien/dcat_collection_catalog-3), while harvested datasets are not.

[volkerjaenisch]

This problem is related to changes with the doubling recognition.