Add comprehensive unit tests to cover edge cases for Delta log path parsing

[hackintoshrao]

This PR introduces new unit tests to validate the Delta Lake log path parsing logic corner cases thoroughly:

1. test_invalid_version_and_part_lengths:

   • Verifies correct handling of invalid version lengths (VERSION_LEN)
   • Tests parsing of invalid multipart checkpoint lengths (MULTIPART_PART_LEN)
   • Ensures proper error handling for invalid UUID lengths (UUID_PART_LEN)

2. test_empty_filename:

   • Confirms that URLs ending with a slash (resulting in empty filenames)
     are correctly rejected

3. test_ok_none_and_unknown_cases:

   • Validates handling of non-numeric version prefixes (Ok(None) cases)
   • Verifies correct parsing of missing file extensions (Ok(None) cases)
   • Ensures proper handling of empty file extensions (Ok(Some) with Unknown type)

These tests significantly improve coverage of edge cases and error
conditions in log path parsing.

[codecov]

Codecov Report

Attention: Patch coverage is 80.76923% with 20 lines in your changes missing coverage. Please review.

Project coverage is 77.86%. Comparing base (025aba8) to head (362372a).
Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
kernel/src/path.rs	80.76%	9 Missing and 11 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #408      +/-   ##
==========================================
- Coverage   78.34%   77.86%   -0.48%     
==========================================
  Files          49       49              
  Lines       10282    10360      +78     
  Branches    10282    10360      +78     
==========================================
+ Hits         8055     8067      +12     
- Misses       1775     1833      +58     
- Partials      452      460       +8     

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[scovich]

Thanks for taking a look at this!

This PR definitely adds some good missed cases, but I think most of the newly added cases were already covered by existing tests.

Suggest to add the missed cases to their respective existing tests (in the same style), rather than making entirely new tests. And maybe update the comments and expect_err calls of those existing cases, since they aren't as nicely described as what this PR does.