text: Title: Enabling data ingestion pipelines
  Body: For now, the ingestion of new data is managed in `backend/worker/quivr_worker/process/process_file.py` or in `backend/core/quivr_core/brain/brain.py` using the `get_processor_class` in `backend/core/quivr_core/processor/registry.py`. 
  
  This approach prevents the construction and use of more complex ingestion pipelines, for instance based on LangGraph. 
  
  We would need to restructure the code so that a Data Ingestion pipeline can be build and used by  `backend/core/quivr_core/brain/brain.py` or by  `backend/api/quivr_api/modules/upload/controller/upload_routes.py` 