Editor: Support editable geometry

[futuresoup]

We are only able to edit geometries from our admin interface. Editing via the admin interface is limited to changes to the geometry itself; geometry styles (stroke and fill colors, opacity) are not editable.

Let's try to make both geometries and geometry styles editable from the app.

[Bilal-io]

We should consider this Leaflet.draw plugin. Here is a demo

[goldpbear]

This seems pretty cool, and maybe preferable to geojson.io since it's a leaflet plugin?

[Bilal-io]

@goldpbear I think this plugin uses GeoJSON since they look very similar, I also did some research in the file. But yes, this would be preferable, since most of the work will be already done by leaflet.draw team. we just have to implement it.