feat: add AI module for LLM interaction and a heuristic for checking code–docstring consistency

[AmineRaouane]

Summary

This PR introduces an AI client for interacting with large language models (LLMs) and adds a new heuristic analyzer to detect inconsistencies between code and its docstrings.

Description of changes

• Added an AIClient class to enable seamless integration with LLMs .
• Implemented a new heuristic analyzer called MatchingDocstringsAnalyzer that detect inconsistencies between code and its docstrings.
• Integrated the new heuristic into the heuristics.py registry.
• Updated detect_malicious_metadata_check.py to include and run this new heuristic.
• Added unit tests to verify correct detection of missing or mismatched docstrings.

Related issues

None

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