Output pathway for DataFrame to GeoJSON

[jpolchlo]

After processing OSM or other inputs into a DataFrame of JTS geometry and added attributes, we may find it useful to produce line-delimited GeoJSON output. Some workflows will prefer this to vectortile output (or for those users who would prefer to use Tippecanoe for VT generation). We should explore how to create such an output pathway.

[mojodna]

This may be as simple as using df.toGeoJSON and writing 'value to a text file.

Sample row:

{"type": "Feature", "geometry": {"type":"Point","coordinates":[-83.1545467,42.2953661]}, "properties":{   "_type": "1",  "id": "18833581",  "tags": "Map(source -> PGS, created_by -> r_coastlines)",  "changeset": "73729",  "updated": "2007-05-30 10:34:26.0",  "validUntil": "null",  "visible": "true",  "version": "1",  "minorVersion": "0"}}

[mojodna]

Bummer that numbers / booleans are converted to strings; maybe that should be addressed on the GeoMesa side.

[mojodna]

Uhh, it also looks like it'll break on values with quotes: https://github.com/locationtech/geomesa/blob/master/geomesa-spark/geomesa-spark-jts/src/main/scala/org/locationtech/geomesa/spark/jts/util/GeoJSONUtils.scala#L42