docstr: Add the app list subparser: manage.py app list
docstr_tok: ["Add","the","app","list","subparser",":","manage.py","app","list"]
code: def _setup_app_list_subparser(subparsers):
      """Add the app list subparser: manage.py app list"""
      generate_subparser(
          subparsers,
          "list",
          description="List all configured app functions, grouped by cluster",
          subcommand=True,
      )
  
file_path: streamalert/streamalert_cli/apps/handler.py
imports: import string
  from streamalert.apps import StreamAlertApp
  from streamalert.shared.logger import get_logger
  from streamalert_cli.apps.helpers import save_app_auth_info
  from streamalert_cli.utils import add_memory_arg, add_schedule_expression_arg, add_timeout_arg, CLICommand, CLUSTERS, generate_subparser, set_parser_epilog
label_desc: Use image node_id 2 for calling the AppCommand obj's underlying member method code with example usage: obj._setup_app_list_subparser(subparsers) without return types