Code review comment for lp://staging/~dpniel/ubiquity/fix-1480430

After our IRC discussion i've dug into this a little more to refresh my memory. So when the buttons are added to the dialog[1] it's done using gtk.Dialog.add_button() [2].

With this approach I can't see any way that set_name() can be called on each button as the add_button takes care of creation for you with no option to add a name.

I'm happy to try and make changes to the UI with a bit of guidance on what would be the best approach to get name properties on the buttons

[1] http://bazaar.launchpad.net/~ubuntu-installer/ubiquity/trunk/view/head:/ubiquity/frontend/gtk_ui.py#L1789
[2] https://lazka.github.io/pgi-docs/#Gtk-3.0/classes/Dialog.html#Gtk.Dialog.add_button