A message "item is not for sale" is snown on parts and assemblies

In version 5.0.6 and later a function to display a message that a part is not for sale if sellable=false is introduced. The default behaviour is to show a message “Item is not for sale” as an information text.

The function can be turned on and off and the message level can be changed between information, warning and error.

See https://signifikant.atlassian.net/wiki/spaces/ASKB/pages/976683009 in the configuration section on how to configure this function.