Automatized changes to license and copyright information

See merge request nomad-lab/parser-gaussian!1

Gaussian parser metadata "configuration_periodic_dimensions" and "simulation_cell" defined for molecules

still failing because a new single_configuration_calculations section should
be opened for every single configuration calculation (for example every geoopt step).

section_system_description -> section_system
cell_associated -> cell_dependent

having files that are distinguished only be case creates problems
with case insensitive filesystems (as typically used on mac and
windows).