Extensible select and enumeration types

and their elements in schema Fill_area_style_arm taking into account BASED_ON types


 closed_curve - EXTENSIBLE GENERIC_ENTITY SELECT
          Circle
          Closed_composite_curve

 external_identification_item - EXTENSIBLE GENERIC_ENTITY SELECT

 fill_area_style_select - EXTENSIBLE GENERIC_ENTITY SELECT
          Hatch_style
          Tile_style

 identification_item - EXTENSIBLE SELECT

 measure_value - EXTENSIBLE SELECT
          any_number_value
          any_string_value
          length_measure
          plane_angle_measure

 point_select - EXTENSIBLE GENERIC_ENTITY SELECT
          Cartesian_point
          Point_on_curve
          Point_on_surface