Report outdated packages imported from a different channel

https://phabricator.apertis.org/T9291

Some Apertis packages come from a different Debian release. In order keep them in sync, active descendant branches are analyzed to determine in which apertis versions they landed. Then, this information is used to report on the dashboard which apertis releases need to be updated.

Signed-off-by: Dylan Aïssi dylan.aissi@collabora.com