Fix sorting a list of transaction items in Python.
Fix sorting a list of transaction items in Python.

Reproducer:
dnf distro-sync where a package replaces (obsoletes) multiple packages.

Traceback:
  File ".../dnf/cli/output.py", line 1095, in list_transaction
    obsoleted = sorted(replaces.get(tsi._item, []))
TypeError: '<' not supported between instances of 'RPMTransactionItemWrapper' and 'RPMTransactionItemWrapper'

Closes: #467
Approved by: j-mracek

Conan-Kudo/libhif,hughsie/libhif,rpm-software-management/libhif,hughsie/libhif,rpm-software-management/libhif,hughsie/libhif,Conan-Kudo/libhif,Conan-Kudo/libhif,rpm-software-management/libhif,rpm-software-management/libdnf,rpm-software-management/libhif,rpm-software-management/libdnf,rpm-software-management/libdnf,hughsie/libhif,Conan-Kudo/libhif,rpm-software-management/libdnf