Multiple fixes in the retrieval, display and logic

- Fix the ordering in datagrepper, the message are processed in the order they are
received so we need to keep that order.
- Fix the ordering in the output, sort the keys
- Fix packages that are first orphaned then unorphaned. If it is by the same person, no
need to show it :)
Rewrites most of the script

- Drop the use of an object
- Have a dedicated method to convert the dict into something we can use
- Query pkgdb changes and retirement actions in one go
- Output unretirements