data model for 3d in viewport and 3d paths.points

[aprossi]

For DOM / 3d geomodels storymaps, one could add to teh [v2] or v3 data model simply the marker with [x, y, z] in local/map coordinates rather tahn [lat, lon]

for example current (v3 candidate) gale

https://gist.github.com/aprossi/c1e2b171b813c67fd42dbd014fdbdecf