Add 'type' field to ExperimentParametersModel

This commit introduces a new 'type' field in the ExperimentParametersModel schema and updates the associated code in `sample.py` to include this field during object creation. Additionally, unnecessary lines and redundant code in `testfunctions.ipynb` have been removed for better readability and maintainability.

backend/app/models.py

@@ -272,6 +272,7 @@ class ExperimentParameters(Base):
     __tablename__ = "experiment_parameters"
     id = Column(Integer, primary_key=True, index=True, autoincrement=True)
     run_number = Column(Integer, nullable=False)
+    type = Column(String(255), nullable=False)
     beamline_parameters = Column(JSON, nullable=True)
     dataset = Column(JSON, nullable=True)
     sample_id = Column(Integer, ForeignKey("samples.id"), nullable=False)