feat: add date, datetime, time, timestamp dtype to to_dataframe

[chelsea-lin]

Thank you for opening a Pull Request! Before submitting your PR, there are a few things you can do to make sure it goes smoothly:

• Make sure to open an issue as a Add 'date_dtype', 'datetime_dtype', 'time_dtype' and 'timetamp_dtype' to the 'to_dataframe' APIs #1546.
• Ensure the tests and linter pass
• Code coverage does not decrease (if any source code was changed)
• Appropriate docs were updated (if necessary)

Fixes #1546 🦕

[tswast]

Loving it so far.

Would you do me a favor and add a system test with "extreme" values like this one, but instead of looking for "object" dtypes, we pass in the ArrowDtype?

python-bigquery/tests/system/test_pandas.py

Line 1063 in e1aa921

def test_list_rows_nullable_scalars_extreme_dtypes(

[tswast]

Thanks!