* 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
ALL_DB_PROVIDERS = [
    'apache.cassandra',
    'apache.drill',
    'apache.druid',
    'apache.hdfs',
    'apache.hive',
    'apache.pinot',
    'cloudant',
    'exasol',
    'microsoft.mssql',
    'mongo',
    'mysql',
    'neo4j',
    'postgres',
    'presto',
    'trino',
    'vertica',
]
all_dbs = list({req for db_provider in ALL_DB_PROVIDERS for req in PROVIDERS_REQUIREMENTS[db_provider]})
_all_requirements = list({req for extras_reqs in EXTRAS_REQUIREMENTS.values() for req in extras_reqs})
EXTRAS_REQUIREMENTS["all"] = _all_requirements
EXTRAS_REQUIREMENTS["all_dbs"] = all_dbs
devel_all = list(set(_all_requirements + doc + devel_minreq + devel_hadoop))
PACKAGES_EXCLUDED_FOR_ALL = []
PACKAGES_EXCLUDED_FOR_ALL.extend(
    [
        'snakebite',
    ]
)
def is_package_excluded(package: str, exclusion_list: List[str]) -> bool: