Distinguish filtered remote from unfiltered in the GUI
Coming from:
https://pagure.io/fedora-workstation/issue/292
There should be added some visual distinction between filtered and unfiltered remote/repo, otherwise users do not know about limited content.
An idea from the downstream ticket was to change the title, which could be done on the Flatpak side (by setting appropriate title by the tool adding the remote), but the remote can be overwritten later, by adding/changing/removing the filter, which would also force the changing app to change the remote title, which is less convenient.
Thus if there's nothing better suggested, a name of $TITLE + " (Filtered)"
can be used as an alternative.