Port debian lister to swh.lister.pattern.Lister API.
The new implementation will produce one instance of ListedOrigin model
per package, notably containing the set of parameters expected by the
debian loader.
The lister is also stateful, meaning only new packages and those with
new found versions since the last listing will be returned.
It has been successfully tested for Debian and Ubuntu distributions.
Porting to the new API was a little bit tricky as that lister is different
from others based on querying a REST API.
Here, each page corresponds to the list of package sources info related
to a given debian suite (e.g. buster, bullseye) and component (e.g. main, universe).
Thus a package name can be seen multiple times across pages so I had to ensure
that the total number of listed origins was accurate in returned lister statistics.
Depends on D4924
Closes T2979