Front end - add additional fields for custom entity attribute definitions

ALL fields that should be there:

• attributeFriendlyName
• attributeName
• defaultValue (we translated this to example)
• defaultValues (set of values when the type is selection_list) (handled by customAttrListDefinitions)
• displayName
• displayType (attributeType already exists, same difference)
• helpText
• name (might want to note with help text that it is recommended to by a URI)

(the following are only used when the type is boolean)

• persistType (always "string") 
• persistValue
• invert (this is a boolean flag)