API for file structure

[pp-mo]

Could be useful to provide the Checker.structure_report output as a re-usable data output

• for general usage from Python code

e.g. (something like)

mesh_struct = Checker(file).structure_report(return_struct=True)  # this is a bit clunky
print('Mesh vars, named : ', mesh_struct.meshes.keys())
print('Connectivities without a mesh : ', mesh_struct.orphan_connectivities.keys())
print('Non-mesh dimensions : ', mesh_struct.nonmesh_dims.keys())
print('Number of non-mesh variables: ', len(mesh_struct.nonmesh_vars))