Tooltip and Popup don't work in GeoJson with MultiPoint geometry

[martinfleis]

Describe the bug
If you have MultiPoint geometry in your GeoJSON, Tooltip and Popup do not work. Normal Points are fine as well as MultiPolygons.

To Reproduce

import json
import folium

geojson = '{"type": "FeatureCollection", "features": [{"id": "0", "type": "Feature", "properties": {"foo": 0}, "geometry": {"type": "MultiPoint", "coordinates": [[0.0, 0.0]]}}, {"id": "1", "type": "Feature", "properties": {"foo": 1}, "geometry": {"type": "MultiPoint", "coordinates": [[1.0, 1.0]]}}, {"id": "2", "type": "Feature", "properties": {"foo": 2}, "geometry": {"type": "MultiPoint", "coordinates": [[2.0, 2.0]]}}, {"id": "3", "type": "Feature", "properties": {"foo": 3}, "geometry": {"type": "MultiPoint", "coordinates": [[3.0, 3.0]]}}, {"id": "4", "type": "Feature", "properties": {"foo": 4}, "geometry": {"type": "MultiPoint", "coordinates": [[4.0, 4.0]]}}]}'

geojson = json.loads(geojson)

m = folium.Map()
folium.GeoJson(
    geojson,
    tooltip=folium.GeoJsonTooltip(["foo"]),
    popup=folium.GeoJsonTooltip(["foo"]),
    marker=folium.CircleMarker(radius=20)
).add_to(m)
m

Expected behavior
Both tooltip and popup should normally work as with any other geometry type.

Environment (please complete the following information):

• Browser [e.g. chrome, firefox]: Safari
• Jupyter Notebook or html files? Jupyter
• Python version (check it with import sys; print(sys.version_info)): 3.9.6
• folium version (check it with import folium; print(folium.__version__)): master
• branca version (check it with import branca; print(branca.__version__)): master

Additional context
xref geopandas/geopandas#2190

Possible solutions
You can explode MultiPoints to Points but that is not a viable solution as it breaks the geometry into pieces.

I can have a look at the fix unless it requires a lot of JavaScript :).

[hansthen]

It looks like this issue is caused by the fact that the popup is bound to the geojson, and not to the individual layers. Not sure why this makes a difference. It may also be an upstream issue in leaflet. In javascript I usually see popups bound to the layers in onEachFeature.