feat: add fit_predict method to ml unsupervised models

[GarrettWu]

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Fixes #<issue_number_goes_here> 🦕

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[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]