Remove the topIcons GNOME Shell extension
In order to unblock the work on the test suite for Tails/Jessie, we've installed the topIcons GNOME Shell extension. This may be acceptable for Tails/Jessie, but IMO it's not a suitable long-term solution. So, for each "applet" we currently have that hijacks the notification area, we want to either drop it, or convert it to a proper GNOME Shell extension.
The Debian maintainer requested help to maintain the gnome-shell-extension-top-icons-plus package because it's currently unmaintained upstream. Besides, this extension does not work on Wayland unless the app that displays the icon is run with
GDK_BACKEND=x11 (we could probably do that for such apps that we ship by default but it won't work for Additional Software Packages).