Support (undirected) Graph

[schnellerhase]

Allow for construction of meshes based on networkx.Graph.

[jorgensd]

How would we then choose the orientation needed for tangent derivatives?:) is there a motivation I missing here?

[schnellerhase]

That would indeed result in a mesh without orientation information 😄 . Allows use cases where a direction is not necessary, should only be a subset of the already present functionality.