Fixed the suggestedVersion calculation, now done via SQL.
The archive repo was getting updated after the regular repo.
In these situations, we didn't have every single app/apk in
memory in order to calculate the suggested version. As a
result, F-Droid ended up choosing a suggested version from
the archived versions, when terhere was actually a newer version
in the database.
This change does all of the calculations in two database queries
now. Although the implementation of the query is not hackey,
they way I get to the code in order to execute the query
is a bit hacky, so most of the implementation is private.