Fix job type assignment and clean up testfunctions file.

Updated job type to reference `experiment.type` in `processing.py` for accurate data handling. Cleaned up and streamlined `testfunctions.ipynb` by removing outdated and redundant code, improving readability and usability.

backend/app/schemas.py

@@ -983,6 +983,7 @@ class JobsResponse(BaseModel):
     updated_at: Optional[datetime]
     data_collection_parameters: Optional[DataCollectionParameters] = None
     experiment_parameters: BeamlineParameters
+    filepath: Optional[str] = None
     slurm_id: Optional[int] = None