Extensible select and enumeration types

and their elements in schema property_distribution_and_model_relationships_schema taking into account BASED_ON types


 characterized_product_definition - EXTENSIBLE SELECT
          product_definition
          product_definition_relationship

 discretised_distribution_model_select - EXTENSIBLE SELECT
          model_property_distribution
          state_definition

 idealised_distribution_select - EXTENSIBLE SELECT
          domain_property
          property_definition