Add-ons section is messy, containing duplicate adds-ons; fails to uninstall PackageKit add-on
The Add-Ons section of the Installed view is unfortunately pretty messy, using gnome-software-46.1-1.fc40:
- openh264 add-on is repeated twice. I actually have three openh264 flatpak extensions installed, two from flathub and one from gnome-nightly, but Software does not disambiguate them. We should never display the same thing twice without explaining why.
- Pinyin and Zhuyin are not uninstallable, while the other ibus adds-ons are. This doesn't make sense; they should at least be parallel.
- The English add-on is listed twice, and each has entirely different metadata. Not OK.
- Worst of all, PackageKit is presented as uninstallable, but nothing happens when clicking Uninstall. At the very least, even if the operation is going to fail, the button state should change to indicate the button was clicked.