Query endpoint throws exception if body is null

[ndr-brt]

Bug Report

Describe the Bug

When the /v1alpha/catalog/query is called with a null request body this exception is thrown:

SEVERE 2024-08-01T07:27:13.475784497 JerseyExtension: Unexpected exception caught
java.lang.NullPointerException
	at java.base/java.util.Objects.requireNonNull(Objects.java:208)
	at org.eclipse.edc.transform.TypeTransformerRegistryImpl.transform(TypeTransformerRegistryImpl.java:57)
	at org.eclipse.edc.catalog.api.query.FederatedCatalogApiController.getCachedCatalog(FederatedCatalogApiController.java:55)

Expected Behavior

to not thrown exceptions, it should consider the null request body as an empty QuerySpec