fix projsync --list-files CSV header

[visr]

Running projsync --list-files returns CSV data like this:

filename,source_id,area_of_use,file_size
at_bev_README.txt,,at_bev,3200
at_bev_AT_GIS_GRID.tif,Austria,at_bev,216878

The column order of the header and data don't match, source_id and area_of_use are swapped. We could swap either the header or the data, in this PR I'm swapping the header.

Here you can see the order of the data:

PROJ/src/apps/projsync.cpp

Lines 608 to 626 in c637eff

	if (!queriedSourceId.empty() && !foundMatchSourceIdCriterion) {
	std::cerr << "Warning: '" << queriedSourceId
	<< "' is a unknown value for --source-id." << std::endl;
	std::cerr << "Known values are:" << std::endl;
	for (const auto &v : source_ids) {
	std::cerr << " " << v << std::endl;
	}
	std::exit(1);
	}
	if (!queriedAreaOfUse.empty() && !foundMatchAreaOfUseCriterion) {
	std::cerr << "Warning: '" << queriedAreaOfUse
	<< "' is a unknown value for --area-of-use." << std::endl;
	std::cerr << "Known values are:" << std::endl;
	for (const auto &v : areas_of_use) {
	std::cerr << " " << v << std::endl;
	}
	std::exit(1);
	}

[rouault]

thanks