debian: Reimplement lister using new Lister API

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.

Closes T2979