Feature/dch notre environnement

[lpi-tn]

This pull request introduces a new scraping plugin for the "Notre Environnement" website and makes supporting changes to integrate it into the project. It also adds new dependencies, utility functions, and comprehensive unit tests to ensure the reliability of the new collector.

NotreEnvironnementCollector Plugin Integration

• Added a new NotreEnvironnementCollector class in welearn_datastack/plugins/scrapers/notre_environnement.py for scraping and extracting metadata and content from the "Notre Environnement" website, including robust error handling and Dublin Core metadata extraction.
• Registered NotreEnvironnementCollector in the scrapers plugin system (welearn_datastack/plugins/scrapers/__init__.py). [1] [2]

Testing Enhancements

• Added a comprehensive test suite for NotreEnvironnementCollector covering successful runs, no-content scenarios, and HTTP errors (tests/document_collector_hub/plugins_test/test_notre_environnement.py).

Utility and Dependency Updates

• Introduced a normalize_text utility function in scraping_utils.py for consistent text normalization.
• Added trafilatura and extruct as dependencies in pyproject.toml to support content extraction and metadata parsing.