Pin icons based on item's class (castle, mountain, etc)

[nicolas-raoul]

All pins on the map look the same, which is a pity.

We should display the Wikidata icon of the item's class (or its parent class etc)

That would make it easy to spot castles, ruins, mountains, townhalls, historical events, administrative subdivisions, etc, without having to click on each item.

I can write the Wikidata query if you want.