/propertiesendpoint, should output the map between property labels and identifiers. list of property identifiers.

• Use a caching mechanism for efficient response times, since the map is heavy to compute on the fly;
• call https://www.wikidata.org/w/api.php?action=wbgetentities&ids=${PID}&props=labels to get the property label. Not needed, already implemented in the front end through getEntityLabel.