Track if a DiscoveredPackage is for the From-side, the To-side or both

[pombredanne]

I want to know if a DiscoveredPackage is for the From-side, the To-side or both.
A package could come from scanning manifests, or from matching and it may be deployed or not deployed. We need to track explicitly if a package is present on the To/From/both as this is then an important filter in the UI and for reporting SBOMs and attribution

[tdruez]

The simplest solution is probably to add a tag field as it is implemented on the resource model.
The extra_data could be used too, but it's not great for filtering purposes that are needed here.