Allow import of Nova Launcher backup

While Nova Launcher and Niagara Launcher work differently and most things, like the layout of apps on the pages and visual customization settings, cannot be carried over into Niagara Launcher, some settings could make sense to import.

Things like, interpreting the dock as favorite apps, folders, pinned shortcuts, renamed apps etc. would work inside Niagara Launcher.

If there is something in particular you would like to carry over from Nova Launcher, please answer below.