Validate edge linestrings

[visr]

So far, the core doesn't do anything with geometries. But if the edge linestring does not start at the from_node_id node point to the to to_node_id node point, that can lead to some very confusing situations, that have already happened. So we should consider validating this.

We should do this in Python on edge.add as well, if a linestring is passed.

In the core, I don't want to start relying on GDAL, but perhaps we can use (parts of) https://github.com/JuliaGeo/GeoPackage.jl.

We can just require snapping, so exact or Float64 approx equality should suffice. Note that I'm talking only about validating the start and end of the linestrings. This should handle both single and multi segment linestrings. Intermediate vertices of linestrings don't need to be validated; although it wouldn't be nice if they lie on Node points.

[visr]

Whilst we plan to do this, we should postpone this until the end of the year, and communicate with @rbruijnshkv because their network generation will have to be updated for this, they have gaps from waterways to node points in the edges.

@DanielTollenaar wrote a Python function to check this separately; could you link that code here?

[DanielTollenaar]

@visr you can find the code here: https://github.com/Deltares/Ribasim-NL/blob/7ede4725205bd9a5786649dc3667f47078a03308/src/ribasim_nl/ribasim_nl/network_validator.py#L93-L100 referring to this function applied for every row in the edge-table: https://github.com/Deltares/Ribasim-NL/blob/7ede4725205bd9a5786649dc3667f47078a03308/src/ribasim_nl/ribasim_nl/network_validator.py#L11-L24