### Overview
Some Executors have their own first class CLI commands (now that’s hardcoding/coupling!) which setup or modify various components related to that Executor.
### Examples
- **5a**) Celery Executor commands: https://github.com/apache/airflow/blob/27e2101f6ee5567b2843cbccf1dca0b0e7c96186/airflow/cli/cli_parser.py#L1689-L1734
- **5b**) Kubernetes Executor commands: https://github.com/apache/airflow/blob/27e2101f6ee5567b2843cbccf1dca0b0e7c96186/airflow/cli/cli_parser.py#L1754-L1771
- **5c**) Default CLI parser has hardcoded logic for Celery and Kubernetes Executors specifically: https://github.com/apache/airflow/blob/27e2101f6ee5567b2843cbccf1dca0b0e7c96186/airflow/cli/cli_parser.py#L63-L99
### Proposal
Update the BaseExecutor interface with a pluggable mechanism to vend CLI `GroupCommands` and parsers. Executor subclasses would then implement these methods, if applicable, which would then be called to fetch commands and parsers from within Airflow Core cli parser code. We would then migrate the existing Executor CLI code from cli_parser to the respective Executor class.

Pseudo-code example for vending `GroupCommand`s:
```python
# Existing code in cli_parser.py
...
airflow_commands: List[CLICommand] = [
GroupCommand(
        name='dags',
        help='Manage DAGs',
        subcommands=DAGS_COMMANDS,
    ),
    ...
]
# New code to add groups vended by executor classes
executor_cls, _ = ExecutorLoader.import_executor_cls(conf.get('core', 'EXECUTOR'))
airflow_commands.append(executor_cls.get_cli_group_commands())
...
```
if name == "app":
        from airflow.providers.celery.executors.celery_executor_utils import app
        return app
    raise AttributeError(f"module '{__name__}' has no attribute '{name}'")
"""
To start the celery worker, run the command:
airflow celery worker
"""
ARG_BROKER_API = Arg(("-a", "--broker-api"), help="Broker API")
ARG_FLOWER_HOSTNAME = Arg(
    ("-H", "--hostname"),
    default=conf.get("celery", "FLOWER_HOST"),
    help="Set the hostname on which to run the server",
)
ARG_FLOWER_PORT = Arg(
    ("-p", "--port"),
    default=conf.getint("celery", "FLOWER_PORT"),
    type=int,
    help="The port on which to run the server",
)
ARG_FLOWER_CONF = Arg(("-c", "--flower-conf"), help="Configuration file for flower")
ARG_FLOWER_URL_PREFIX = Arg(
    ("-u", "--url-prefix"),
    default=conf.get("celery", "FLOWER_URL_PREFIX"),
    help="URL prefix for Flower",