feat: Simplify fallback architecture and remove length restrictions

fix(llm-clients): relax abnormal response detection threshold for medical advice

refactor: improve multilayer logic in llm_clients to to enhance functionality and improve performance based on medical or unmedical issues

feat(user_prompt): update UserPromptProcessor to integrate Llama3-Med42-70B and enhance query validation; add unit tests for condition extraction and matching mechanisms

feat(llm_clients): enhance MeditronClient to support local model loading and improve error handling

WIP(llm_clients): add MeditronClient for medical query processing with Hugging Face integration