feat: add fit_predict method to ml unsupervised models

[GarrettWu]

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 bug/issue before writing your code! That way we can discuss the change, evaluate designs, and agree on the general idea
• Ensure the tests and linter pass
• Code coverage does not decrease (if any source code was changed)
• Appropriate docs were updated (if necessary)

Fixes #<issue_number_goes_here> 🦕

[review-notebook-app]

Check out this pull request on 

See visual diffs & provide feedback on Jupyter Notebooks.

---

Powered by ReviewNB

[shuoweil]

Please check the failed presubmit

[GarrettWu]

Please check the failed presubmit

Unrelated

FAILED tests/system/small/test_series.py::test_timestamp_astype_string - Asse...
FAILED tests/system/small/test_series.py::test_float_astype_json[raise] - Ass...
FAILED tests/system/small/test_series.py::test_float_astype_json[null] - Asse...
FAILED tests/system/small/test_series.py::test_float_astype_json_str - Assert...
FAILED tests/system/small/test_series.py::test_string_astype_json_in_safe_mode
FAILED tests/system/small/test_series.py::test_string_astype_json_raise_error
FAILED tests/system/small/test_series.py::test_json_astype_others_raise_error[to_float]
FAILED tests/system/small/test_series.py::test_json_astype_others_raise_error[to_bool]
FAILED tests/system/small/test_series.py::test_json_astype_others_raise_error[to_string]
FAILED tests/system/small/test_series.py::test_json_astype_others_in_safe_mode[to_int]
FAILED tests/system/small/test_series.py::test_json_astype_others_in_safe_mode[to_float]
FAILED tests/system/small/test_series.py::test_json_astype_others_in_safe_mode[to_bool]
FAILED tests/system/small/test_series.py::test_json_astype_others_in_safe_mode[to_string]