Fix 3D Delaunay for non-manifold geometries
With a single surface connected to a volume, if the 3D Delaunay modifies the volume boundary mesh we get hanging nodes.
We should precompute non-connected volumes and apply the algo to each non-connected aggregate separelely. This would also improve the mesh quality and speed for close non-connected objects.
Also: we need to fix the 1D mesh in all cases.