[BUG] cppfront fails on valid cpp1 syntax for importing module partitions

[farmerpiki]

module;

export module utils:part2;
import :part1;

results in part2.cpp2(4,1): error: a namespace-scope object must have an initializer

there currently is a workaround, explicitly writing, but that might result in duplicate exports if it's needed in multiple places
export import :part1;

[JohelEGP]

This is resolved by #569.
The PR is closed, but I still keep the branch up-to-date (https://github.com/JohelEGP/cppfront/tree/cpp_modules).