Vector graphics fix

[Jonathhhan]

changes string to std::string.

[dimitre]

I think this one could be replaced by of::filesystem::path

[dimitre]

Hello @Jonathhhan do you want to update it to filesystem?
if not we can merge as it is and then rework later

[Jonathhhan]

@dimitre I tested it with of::filesystem, but maybe I do something wrong (at least the SWIG bindings do not work with that). So I would say, leave it as is for now.