Show superposed POIs

[frodrigo]

On lasts zoom level clustering is disabled. But superposed POI cannot be show and clisck by the user.

An alternate clustering display should be used.

Ideas:

• shift point locations
• Make cluster manually expendable

-> Make it as external MapLibre Plugin / check if one not already exists

[frodrigo]

• https://leaflet.github.io/Leaflet.markercluster/example/marker-clustering-realworld.388.html
• https://github.com/mapbox/mapbox-gl-js/issues/7120
  • https://maplibre.org/maplibre-gl-js/docs/API/classes/GeoJSONSource/#getclusterleaves
• https://github.com/nazka/map-gl-js-spiderfy