Extensible select and enumeration types

and their elements in schema SHAPE_TOLERANCE_SCHEMA taking into account BASED_ON types


 area_unit_type - EXTENSIBLE ENUMERATION
          circular
          rectangular
          square

 characterized_product_definition - EXTENSIBLE SELECT
          product_definition
          product_definition_relationship

 datum_reference_modifier - EXTENSIBLE SELECT
          datum_reference_modifier_with_value
          simple_datum_reference_modifier

 datum_reference_modifier_type - EXTENSIBLE ENUMERATION
          circular_or_cylindrical
          distance
          spherical

 geometric_tolerance_modifier - EXTENSIBLE ENUMERATION
          any_cross_section
          common_zone
          each_radial_element
          free_state
          least_material_requirement
          line_element
          major_diameter
          maximum_material_requirement
          minor_diameter
          not_convex
          pitch_diameter
          reciprocity_requirement
          separate_requirement
          statistical_tolerance
          tangent_plane

 item_identified_representation_usage_definition - EXTENSIBLE GENERIC_ENTITY SELECT
          geometric_tolerance
          represented_definition

 simple_datum_reference_modifier - EXTENSIBLE ENUMERATION
          any_cross_section
          any_longitudinal_section
          basic
          contacting_feature
          degree_of_freedom_constraint_u
          degree_of_freedom_constraint_v
          degree_of_freedom_constraint_w
          degree_of_freedom_constraint_x
          degree_of_freedom_constraint_y
          degree_of_freedom_constraint_z
          distance_variable
          free_state
          least_material_requirement
          line
          major_diameter
          maximum_material_requirement
          minor_diameter
          orientation
          pitch_diameter
          plane
          point
          translation