PwImmigrant does not parse bands

[lekah]

When importing a bands-calculation, the PwImmigrant does not create a BandsData instance.
This needs to be implemented and the documentation updated.

[lekah]

Would the method calc._set_retrieve_temporary_list(retrieve_temporary_list) enforce the copying of the remote wavefunctions? Retrieve_temporary_list is set to
xmlpaths = os.path.join(calc._OUTPUT_SUBFOLDER, calc._PREFIX + '.save', 'K*[0-9]', 'eigenval*.xml') retrieve_temporary_list = [[xmlpaths, '.', 2]]

[lekah]

The above comment indeed fixes this problem:
xmlpaths = os.path.join('out', 'aiida' + '.save', 'K*[0-9]', 'eigenval*.xml') retrieve_temporary_list = [[xmlpaths, '.', 2]] calc_scf._set_retrieve_temporary_list(retrieve_temporary_list) with transport as open_transport: calc_scf.create_input_nodes(open_transport) calc_scf.prepare_for_retrieval_and_parsing(open_transport)

[sphuber]

This is a duplicate of #53