use same sort function as on PAUSE

Parse::CPAN::Packages::Fast has a function to quickly find a module from 02packages.details.txt using binary search. Unfortunately, this does not work if the packages file is sorted in a case-sensitive manner, like it happens with build02packages.pl. With this change the sort order should be the same like the original 02packages.details.txt.

See also https://rt.cpan.org/Public/Bug/Display.html?id=96615 for the original bug report.