Improve the map to handle compound heritage sites

[seav]

Some heritage sites, like the WHS “Baroque Churches of the Philippines”, WHS “Rice Terraces of the Philippine Cordilleras”, and the NCT “Bohol Watchtowers”, are not a single site but rather a group of sites that are located in different places. The map currently does not have any good way of representing these sites on the map.

On the Wikidata side, the data modeling may need to be updated to properly reflect the relationships between the compound and individual sites via “has part” (P527), “part of” (P361), and “applies to part” (P518) properties.

[seav]

For the map, a possible solution is to temporarily uncluster the map markers for the individual sites and add tooltips instead of popups when a compound site is displayed.