Update status icons immediately after backup

[juk0de]

What's your idea?

I like the new icons that are showing the current state for each game, so I can easily see which one needs to backed up. However, there's no way to check if a backup was successful, unless you run "preview" again (which can take a while to complete). Also, it's somewhat confusing that the status icons don't change automatically after a backup.

As a solution, I suggest updating the status icons right after a backup (only if the backup was successful, of course). In order to make sure the backup is valid, you could also run the "preview" code again automatically, but only for those games where a new backup has actually been created (i. e. those marked with Δ and selected by the user). That should be fast enough for most cases.

You could also display a modal window with a success message, but I'm not a big fan of modal windows (I would also like an option to disable the one where you start a backup, tbh). Imho, the approach described above, combined with https://github.com/mtkennerly/ludusavi/issues/159, would be a nice usability improvement :relaxed: