

**Description**

We are using a 3rd party executor which has the ability to use multiple queues, however the `default_queue` is defined under the `celery` heading and is used regardless of the executor that you are using.

See: https://github.com/apache/airflow/blob/2.0.1/airflow/models/baseoperator.py#L366

It would be nice to decouple the default_queue configuration argument away from the celery section to allow other executors to utilise this functionality with less confusion.

**Are you willing to submit a PR?**

Yep! Will open a pull request shortly


**Related Issues**

Not that I'm aware of.

airflow/cli/cli_parser.py
ActionCommand(
        name='widgets',
        help='Get information about registered connection form widgets',
        func=lazy_load_command('airflow.cli.commands.provider_command.connection_form_widget_list'),
        args=(
            ARG_OUTPUT,
            ARG_VERBOSE,
        ),
    ),
    ActionCommand(
        name='hooks',
        help='List registered provider hooks',
        func=lazy_load_command('airflow.cli.commands.provider_command.hooks_list'),
        args=(ARG_OUTPUT, ARG_VERBOSE),
    ),
    ActionCommand(
        name='behaviours',
        help='Get information about registered connection types with custom behaviours',
        func=lazy_load_command('airflow.cli.commands.provider_command.connection_field_behaviours'),
        args=(ARG_OUTPUT, ARG_VERBOSE),
    ),
)
USERS_COMMANDS = (
    ActionCommand(
        name='list',
        help='List users',
        func=lazy_load_command('airflow.cli.commands.user_command.users_list'),
        args=(ARG_OUTPUT, ARG_VERBOSE),
    ),
    ActionCommand(