Retrieves property values from entities in the Wolfram Knowledgebase.
EntityValue[entity, property]
EntityValue[{entity1, entity2, …}, property]
EntityValue[class, property]
EntityValue[entity, {property1, property2, …}]
EntityValue[ents, {property1, property2, …}]
EntityValue[x, y]
→ EntityValue[x, y]