Extensible select and enumeration types

and their elements in schema Product_as_individual_assembly_arm taking into account BASED_ON types


 extended_value_with_unit - EXTENSIBLE SELECT
          Value_limit
          Value_range
          Value_with_unit

 groupable_item - EXTENSIBLE GENERIC_ENTITY SELECT

 identification_item - EXTENSIBLE SELECT
          Product_as_individual
          Product_as_individual_version
          Product_as_individual_view
          Product_class

 measure_value - EXTENSIBLE SELECT
          any_number_value
          any_string_value
          length_measure
          plane_angle_measure