Language Option, Relevance Score,

[WagnerJon]

• added option to choose the prefered language query in the benchmark_data.yaml
• added relevance score
• added test function with reassurance

unsure about the implementation of these things

[slobentanzer]

TODO:

• move end-to-end query generation to query generation only (use method _generate_query)
• use dedicated query_language parameter in _generate_query() method (remove string engineering from test)
• check rag_interpretation tests to reuse the evaluation_conversation fixture (contest.py)

[slobentanzer]

@WagnerJon you opened a new PR #225, should this one be closed?