`Asset` that points to a `Catalog` shouldn't rely on the `DataAddress`

[ndr-brt]

Feature Request

An Asset can be created with a isCatalog property, that targets it as a catalog dataset entry that points to another catalog.

See:

Connector/core/control-plane/control-plane-catalog/src/main/java/org/eclipse/edc/connector/controlplane/catalog/DatasetResolverImpl.java

Line 111 in 52cec0c

.endpointUrl(asset.getDataAddress().getStringProperty(HttpDataAddressSchema.BASE_URL, null))

and

Connector/core/control-plane/control-plane-catalog/src/main/java/org/eclipse/edc/connector/controlplane/catalog/DefaultDistributionResolver.java

Line 42 in 52cec0c

.format(asset.getDataAddress().getType())

This should change, as DataAddress is meant to be deprecated and removed in the upcoming versions

Which Areas Would Be Affected?

Asset, Catalog

Solution Proposal

My proposal would be to define another property, similarly to isCatalog, there should be additional ones called, like catalogUrl and catalogFormat.
The change should help the user to understand how their Assets need to be upgraded with a meaningful warning and fallback mechanism with deprecation.