Extract package mangagement scripts to dedicated repository

[tkilias]

Background:

• The scripts are used for all falvors, but at some point each flavor type should get its own repository, so we need to externalize these scripts
• It enforces test separation which means your tests test smaller parts

Tasks:

• Extract code to new repository
• Extract tests
• Setup CI for new repository
• Create package management such that language container flavors can import it (probably as source packages)

[tkilias]

./ext/scripts gets used by the flavor, for that reason, we need to build a release artifact which we can download in the flavor

this will be another release artifact which contains these scripts and its dependencies
./scripts/generate_package_diffs_for_flavors
./scripts/update_apt_package_in_package_list.sh
./scripts/find_apt_package_in_package_list.sh