List outdated packages in packages query

Adding the outdated parameters to the packages query will list the
outdated packages. This finalizes the work done previously.

Optimizations will come next, such as only storing packages from
upstream apt sources, when these are already in the package history.

More reports and further details in the package (outdated) list are
also planned.

Database migration is required.

Signed-off-by: Christoph Kassen <c.kassen@telekom.de>
Merge pull request #32 from TelekomCloud/feature/outdated_packages

List outdated packages in packages query