Default to non-blank nodes for feature uris

[josephguillaume]

Blank nodes prevent a feature from being referenced

Uri can default to slugifying any name field

[josephguillaume]

Replace creation of blank node in GeoJSONtoRDF:

edit_rdf_geojson/scripts/rdf_geojson.js

Line 64 in ef6f086

let rdf_feature = $rdf.blankNode();

[josephguillaume]

New feature is created without properties, so if a human readable URI is needed, it needs to be added when editing properties.
pm:create could bring up dialog.
Specific data schema could be required, including pattern for creating URI.

[josephguillaume]

In 598d76e, property editor shown after feature is created