Cleanup InventoryPrinter API

The current draft Inventory Printer service API has some problems:

• The PrinterMode class does not really describe a mode but rather a format. So it should be called Format instead.
• The InventoryPrinter.print method somewhat randomly lists its arguments. I think they should be reorded to read PrintWriter, Format (aka PrinterMode), boolean.
• The InventoryPrinter requires three service registration properties. While it makes absolute sense to have them defined, I am not sure, whether we should require them. So I propose the following defaults:
• ..format: Format.TEXT
• ..name: InventoryPrinter+<service.id>
• ..title: same as name
• Rename the InventoryPrinter service properties removing the "CONFIG_" prefix