Use interpolated points along LineStrings for sampling

[veniversum]

ariadne-cartograph/update_ways_metadata.py

Lines 25 to 28 in 448ba94

	coordinates = json.loads(geojson)['coordinates']
	values = []
	for coord in coordinates:
	values.append(provider.get_value(*coord))

Currently, our sampling algorithm uses the coordinates (points) in LineString objects. This poses an issue since LineStrings can contain different number of points, and the points may not be at evenly spaced intervals.

A better sampling algorithm can sample values from N equally spaced, points along the LineString, which should provide a better estimate of the value of the LineString overall.

The following function in the Shapely library could be useful:
https://toblerity.org/shapely/manual.html#object.interpolate