[cnx] Use entity_type instead of entity_metas()['type'] The latter is deprecated in favor of the former which has been introduced on cnx to replace it.

[entity] Reimplement and deprecate entity.cw_metainformation It shouldn't rely anymore on cnx.entity_metas which is itself deprecated, and the cw_metainformation API is similarly not needed anymore, access directly to cwuri / cw_source if needed. Related to #15538288