Additional Fields in Filament Tab#549

Additional fields should be available within the Filament tab, including bed temp range and nozzle temp range. But there are other fields that could be user populated as well, like flow ratio, pressure advance and max flow volume. This would be handy for those people who just use SP to manage their filament inventory and not use all the other features of SP.
I’ve already made the suggestion for the Open Filament Database to house the bed and nozzle temps for each variant instead of putting it under a slicer setting, since the bed and nozzle temps are not slicer specific, but are filament specific.