Switch bookmarks back from paginated to scrollable

[orblivion]

When I tried before, the scroll wheel doesn't work on the bookmarks menu on the left. Instead, it just zooms. It acts on the map below the menu.

Ideas:

• See how the heck Leaflet Search does it with its search results! Just do that.
• Mouse scroll propagates, which we don't want. See:
  • https://stackoverflow.com/questions/52309356/overlay-div-over-leaflet-and-stop-mouse-action-propagation
  • https://github.com/Leaflet/Leaflet/pull/5280/files
  • https://gis.stackexchange.com/questions/104507/disable-panning-dragging-on-leaflet-map-for-div-within-map