DelayedVector does not support geoparquet

[JeroenVerstraelen]

Minimal process graph: https://gist.github.com/JeroenVerstraelen/899f5fbc04e7b5c2c025a390af3d6802

The issue is in to_save_result

def to_save_result(data: Any, format: Optional[str] = None, options: Optional[dict] = None) -> SaveResult:
    ....
    elif isinstance(data, DelayedVector):
        if format is None or format.lower() == "json":
            # TODO #114 EP-3981 add vector cube support: keep features from feature collection
            geojsons = [mapping(geometry) for geometry in data.geometries_wgs84]
            return JSONResult(geojsons, format=format, options=options)
        if format.lower() == "geojson":
            return JSONResult(data.geojson, format="geojson", options=options)
        raise ValueError(f"Unsupported format {format} for DelayedVector")
    ....