Comment 0 for bug 1815761

[Impact]
Dpkg::Post-Invoke is run only when dpkg had to be run. We'd like to be able to show some extra output even if no changes had been made. Imagine "the user disabled the security repo, and does not get any updates shown scenario" - we'd like to be able to tell them that there are security updates available after all.

[Test case]
To be updated once the mechanism is in place, but basically perform an upgrade w/o changes, and make sure the specified hook runs at the end.

[Regression potential]
No-change upgrades/install can now fail if this new hooks fail.