Catalog types must be serialized as part of the catalog property

[jimmarino]

Bug Report

Describe the Bug

Currently, (sub)catalogs of type Catalog are serialized as part of the dataset property in a catalog. Per the DCAT 3 specification, this should be part of the catalog property.

This change needs to be made in the JsonObjectFromCatalogTransformer to filter on types:

        var datasets = catalog.getDatasets().stream()
                .map(offer -> context.transform(offer, JsonObject.class))
                .collect(toJsonArray());