Expose sys module constants in rust level - #2295

I'm not sure... I feel like it doesn't totally make sense to have it in the stdlib directory, since it's more a function of the python interpreter rather than the standard library, and that's why CPython has it as Python/sysmodule.c. Like, why not put the builtins module in stdlib/? I think it's the same sort of thing.

I removed the movnig part and remained only constant exposure part