Changes to List model files

the response property files/items/created_at became nullable for the status 200

response property files/items/deleted_rev list-of-types was widened by adding types integer null and string to media type application/json of response 200

response property files/items/rev list-of-types was widened by adding types integer null and string to media type application/json of response 200

added the optional property files/items/active_processing_generation to the response with the 200 status

added the optional property files/items/lifecycle_status to the response with the 200 status

added the optional property files/items/processing_error_code to the response with the 200 status

added the optional property files/items/processing_error_message to the response with the 200 status

added the optional property files/items/processing_stage to the response with the 200 status

added the optional property files/items/processing_warnings to the response with the 200 status