change creation date to schema:datePublished

project/dalia/query/items/metadata/one_to_one_metadata.py

project/dalia/query/items/search/text_search_query.py

project/dalia/rdf/namespace/SCHEMA.py

...ery/items/facets/test_existing_facet_items_in_database.py

...ct/dalia/query/items/metadata/test_one_to_one_metadata.py

tests/project/dalia/query/items/search/test_count.py

tests/project/dalia/query/items/search/test_text_search.py