Builder v2: show path to resulting files at the end of build process

[marmarta]

The problem you're addressing (if any)

When building packages with builder v2, I need to guess/tab-complete what files were built. I don't always know what exact version I'll get, especially when building pull requests for testing.

The solution you'd like

At the end of the builder output, show what files were created (preferably full path to artifacts/repository directory or what not).

The value to a user, and who that user might be

Makes it much more convenient to do something with the built package (e.g. scp it to a testing laptop).