Fix search_dates language fallback

[Kill1ngPig]

Summary

Fix search_dates() so it can fall back to other explicitly provided languages when the initially selected language does not find any dates.

Fixes #1326.

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Problem

When search_dates() is called with multiple languages and STRICT_PARSING=True, the language selection step may choose a language that cannot parse the date expression. In that case, the current implementation stops after the first selected language and returns no dates, even if another explicitly provided language can parse the same text.

For example, this French date is parsed correctly with languages=["fr"], but was previously dropped when several languages were provided:

"Date de facture 23 juillet 2020 Condition Redevable livraison FR"

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Changes

• Keep the existing detected/selected language as the first parsing attempt.
• When multiple languages are explicitly provided, try the remaining candidate languages if the first one returns no dates.
• Return the first language that successfully finds dates.
• Add a regression test for the French STRICT_PARSING=True case from search_dates() silently drops a French date when STRICT_PARSING=True and multiple languages are passed #1326.

This is not specific to French or to the FR suffix. It handles the broader case where the first selected language fails but another user-provided language can parse the date.

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Tests

python -m pytest -p no:cacheprovider tests/test_search.py tests/test_clean_api.py -q

Result:

262 passed

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.12%. Comparing base (075712f) to head (e329bef).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1331      +/-   ##
==========================================
+ Coverage   97.10%   97.12%   +0.01%     
==========================================
  Files         235      235              
  Lines        2904     2917      +13     
==========================================
+ Hits         2820     2833      +13     
  Misses         84       84              

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[AdrianAtZyte]

Please, run pre-commit.

[Kill1ngPig]

Thanks for the reminder. I ran pre-commit run --all-files locally and pushed the formatting changes in e329bef.