Minor changes - Etienne improvements

[PercheEtienne]

• Add 3 functions in Entity.js in order to generate setters functions : (generateSetterFunction, generateAddItemToListFunction, generateAddItemsToListFunction) with the checking of type
• Add the tests linked to the functions
• Add an non-undefined eventID and recordTime in EPCIS Document examples
• Use the functions in almost all the setters