In addition to fetchall, also support df(), pl(), arrow() and fetchnumpy()

[jovezhong]

Today https://github.com/timeplus-io/proton-python-driver/blob/develop/proton_driver/dbapi/cursor.py only support fetchall() to return the Python object. One user suggests us supporting dataframe out of box.

https://duckdb.org/docs/api/python/overview.html#result-conversion

[jovezhong]

Update, the Client supports dataframe query and insert, but the connect/cursor cannot Sample code https://github.com/timeplus-io/proton-python-driver/blob/develop/example/pandas/dataframe.py

Better to add those dataframe support in connect/cursor too