Update the implementation of pack-redundant for performance in a
repository with many packfiles.
* sc/pack-redundant:
pack-redundant: consistent sort method
pack-redundant: rename pack_list.all_objects
pack-redundant: new algorithm to find min packs
pack-redundant: delete redundant code
pack-redundant: delay creation of unique_objects
t5323: test cases for git-pack-redundant