Fix benchmark bugs

[santo0]

I wasn't able to run the benchmarks with pytest tests/ -s because of some small bugs .

• When initiating RAGConfig in test_benchmarks.py, we were using deprecated params (chunk_config, pool_size, seg_filter and model_path). Use chunk_mode instead of chunk_config.
• make_artifacts_directory() is deprecated, use get_artifacts_directory() instead.
• Correct handling of load_artifacts(...)
• Avoid using console if None.