packagekit: Check app's management plugin also by the plugin name
The packagekit plugin is split into subplugins, where each is a different instance, but the code expects to work on GsApp-s created by a different subplugin, where the compare on the plugin instance address does not work.
Noticed this when looking on #1562 (closed) (the Updates
page showed a Download
button, but whenever I clicked it and the download finished the button stayed as it was, it was not changed to the Restart & Update
).
An alternative way to address this is to merge the subplugins into a single plugin.