Switch to uv - converters/snowflake

[MonkeyCanCode]

As per ML, we want to proceed with more standard layout for python project by using uv. Here are the changes made in this PR:

1. Added LICENSE and NOTICE (see above for reference)
2. Updated README.md with instructions around uv
3. Updated pyproject.toml with PEP 639
4. Added pyproject.toml (unlike keywords in python/, this one has an extra entry for Snowflake)
5. Added uv.lock
6. Converted project from single python script file into module
7. Updated test case to use module instead of loading single python script file into class path

Sample validation:

➜  honeydew git:(switch_to_uv_snowflake) uv sync
Resolved 8 packages in 150ms
      Built honeydew-osi @ file:///Users/yong/Desktop/GitHome/ossie/converters/honeydew
Prepared 1 package in 349ms
Uninstalled 1 package in 1ms
Installed 1 package in 1ms
 ~ honeydew-osi==0.2.0.dev0 (from file:///Users/yong/Desktop/GitHome/ossie/converters/honeydew)
➜  honeydew git:(switch_to_uv_snowflake) ✗ uv run pytest
========================================================================== test session starts ===========================================================================
platform darwin -- Python 3.13.0, pytest-9.1.1, pluggy-1.6.0
rootdir: /Users/yong/Desktop/GitHome/ossie/converters/honeydew
configfile: pyproject.toml
testpaths: tests
collected 128 items

tests/test_honeydew_osi_converter.py ............................................................................................................................. [ 97%]
...                                                                                                                                                                [100%]

============================================================================ warnings summary ============================================================================
tests/test_honeydew_osi_converter.py::test_empty_or_whitespace_metric_expression_skipped[expression0]
tests/test_honeydew_osi_converter.py::test_empty_or_whitespace_metric_expression_skipped[expression1]
  /Users/yong/Desktop/GitHome/ossie/converters/honeydew/src/honeydew_osi_converter.py:489: UserWarning: Metric 'bad_m': no entity reference found in expression; assigning to 'orders'
    warnings.warn(

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
==================================================================== 128 passed, 2 warnings in 0.58s =====================================================================