Display version history of installed package if package is installed

Currently, for an uninstalled package, the version history of the package from remote appstream source is displayed - which is correct. But, for an installed package too we currently display the version history from remote appstream source - which is incorrect.

This issue is made worse by the fact that remote appstream sources contain only the N most recent versions ( Debian Appstream N=4 ). So, we could end up in a scenario where we display versions in the version history, and none of the versions are actually installed in the system. This is the issue reported in #2250.

With this fix, for an installed package, we now display the version history of the installed package from local appstream metadata ( which contains the full version history as provided by package upstream ).

Fixes: #2250