proof_lib.gds struct names contain spaces, that makes them illegal cell names in oasis

[stefanottili]

RobustPath: scale_width False
RobustPath: scale_width True
FlexPath: scale_width False
FlexPath: scale_width True

klayout by default will convert the "illegal characters" to '*', but it's best practice to avoid these in struct/cellnames

[heitzmann]

Done!