* and stop setting default values in python operator code, so defaults can be set at the server side.

This issue is just for the PR and questions from maintainers. 
setup.py
"""
    For Python 3.6+ the dictionary order remains when keys() are retrieved.
    Sort both: extras and list of dependencies to make it easier to analyse problems
    external packages will be first, then if providers are added they are added at the end of the lists.
    """
    sorted_requirements = dict(sorted(EXTRAS_REQUIREMENTS.items()))
    for extra_list in sorted_requirements.values():
        extra_list.sort()
    return sorted_requirements
EXTRAS_REQUIREMENTS = sort_extras_requirements()
PREINSTALLED_PROVIDERS = [
    'ftp',
    'http',
    'imap',
    'sqlite',
]
def get_provider_package_from_package_id(package_id: str) -> str: