`write_csv` does not work for map with insets

[adisidev]

cartogram-cpp/src/cartogram_info/cartogram_info.cpp

Lines 227 to 232 in 4fa3ac7

	// Fill up the rows with the IDs and target areas
	for (const auto &[id, inset_pos] : gd_to_inset_) {
	const auto &inset_state = inset_states_.at(inset_pos);
	const auto target_area = inset_state.target_area_at(id);
	csv_rows.push_back({id, std::to_string(target_area)});
	}