Extensible select and enumeration types

and their elements in schema Document_properties_arm taking into account BASED_ON types


 external_identification_item - EXTENSIBLE GENERIC_ENTITY SELECT
          Document_definition
          File

 measure_value - EXTENSIBLE SELECT
          any_number_value
          any_string_value
          length_measure
          plane_angle_measure

 property_assignment_select - EXTENSIBLE SELECT
          Document_definition
          File

 represented_definition - EXTENSIBLE SELECT
          Assigned_property
          Independent_property