Extensible select and enumeration types

and their elements in schema Activity_method_implementation_mim taking into account BASED_ON types


 classification_item - EXTENSIBLE GENERIC_ENTITY SELECT
          action_method_relationship
          group

 groupable_item - EXTENSIBLE GENERIC_ENTITY SELECT
          action_method_relationship

 identification_item - EXTENSIBLE SELECT
          action_method_relationship

 versionable_item - EXTENSIBLE SELECT