Getting all subpackages/"super"packages of an apk_package

Hello,

as far as I can see it's currently not possible to get all subpackages of a package or what the main package of a subpackage is via libapk. This is problematic for apk-polkit, since it allows fine grained upgrades from users: By default they're presented with an update view in GNOME Software that allows them to either update all packages at once, or to update them one by one:

Note: In this case only flatpaks are ready to be updated, I updated my system before taking the screenshot, but I hope you get the point.

The problem is when an user upgrades a subpackage, e.g. gnome-software-dbg. Upgrading the subpackage doesn't upgrade the mainpackage (since apk-polkit specifies APK_SOLVERF_IGNORE_UPGRADE, so users don't end up updating more than they asked for), which could lead to unexpected results for the user. It'd be best if apk-polkit could tell subpackages and mainpackages apart from each other somehow, so subpackages can be hidden from the view when they main package also is scheduled to be updated.