Replace stated in reference with a more appropriate one

[marfox]

see the following threads:

1. https://www.wikidata.org/wiki/Topic:V6cc1thgo09otfw5
2. https://www.wikidata.org/wiki/Wikidata:Project_chat/Archive/2019/09#Best_reference_for_statements_generated_by_AI

Proposed options that can be implemented:

• replace with based on heuristic P887;
• add a deprecated rank and replace with reason for deprecation (P2241) = "human confirmation required";

[marfox]

We opt for the simplest solution, after some discussion about P887 constraints, see https://www.wikidata.org/wiki/Property_talk:P887#Best_value_for_AI_data : replace reference (stated in, catalog item ) with (based on heuristic, artificial intelligence)