extract filename from pyfive S3 Dataset correctly

[valeriupredoi]

Description

Dataset.id._filename currently returns None for an S3 Dataset (which is a pyfive Dataset)
Closes #199

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• This pull request has a descriptive title and labels
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[valeriupredoi]

converting this to Draft for now, I am not seeing anything wrong on the GHA machines, it's just the tests on my machine that don't pick up the _filename - no, I spoke with my rear, it still fails there too, it's just that that test is skipped on GHA - still keeping it Draft since I needs to fix the tests

This is the test that fails at PyActiveStorage: https://github.com/NCAS-CMS/PyActiveStorage/actions/runs/22106044823/job/63888954418

I'll clean up and fix tests here, and add a test case, tomorrow 🍺

[codecov]

Codecov Report

❌ Patch coverage is 75.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 77.62%. Comparing base (9f9e955) to head (b5d1d62).
⚠️ Report is 9 commits behind head on main.

Files with missing lines	Patch %	Lines
pyfive/h5d.py	75.00%	0 Missing and 1 partial ⚠️

❌ Your patch status has failed because the patch coverage (75.00%) is below the target coverage (100.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #197      +/-   ##
==========================================
- Coverage   77.62%   77.62%   -0.01%     
==========================================
  Files          15       15              
  Lines        3124     3128       +4     
  Branches      497      499       +2     
==========================================
+ Hits         2425     2428       +3     
  Misses        573      573              
- Partials      126      127       +1     

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[valeriupredoi]

@bnlawrence @davidhassell it'd be good to have this in the sooner the better, one test fail in PyActiveStorage because of this (the test manipulating already-loaded datasets that need file names extracted from the Dataset's metadata)

[davidhassell]

Hi V - looks good, with one minor change.
Cheers,
David

[valeriupredoi]

Hi V - looks good, with one minor change. Cheers, David

mega, thanks very much @davidhassell - could you pls Approve? 🍻