win32: Fix resource-based imports
g_build_filename does not work on URIs on Windows as it will use \ which are only valid file separators, not URI separators. We should stick to the GIO child APIs and avoid using GLib primitive file APIs.
g_build_filename does not work on URIs on Windows as it will use \ which are only valid file separators, not URI separators. We should stick to the GIO child APIs and avoid using GLib primitive file APIs.