Refactor Dewar service methods and improve field handling

Updated Dewar API methods to use protected endpoints for enhanced security and consistency. Added `pgroups` handling in various frontend components and modified the LogisticsView contact field for clarity. Simplified backend router imports for better readability.

backend/app/routers/dewar.py

@@ -298,17 +298,17 @@ def generate_label(dewar):
     c.drawString(2 * cm, y_position, f"Unique ID: {dewar.unique_id}")
     y_position -= line_height
 
-    if dewar.contact_person:
-        contact_person = dewar.contact_person
+    if dewar.contact:
+        contact = dewar.contact
         c.drawString(
             2 * cm,
             y_position,
-            f"Contact: {contact_person.firstname} {contact_person.lastname}",
+            f"Contact: {contact.firstname} {contact.lastname}",
         )
         y_position -= line_height
-        c.drawString(2 * cm, y_position, f"Email: {contact_person.email}")
+        c.drawString(2 * cm, y_position, f"Email: {contact.email}")
         y_position -= line_height
-        c.drawString(2 * cm, y_position, f"Phone: {contact_person.phone_number}")
+        c.drawString(2 * cm, y_position, f"Phone: {contact.phone_number}")
         y_position -= line_height
 
     if dewar.return_address:
@@ -368,7 +368,7 @@ async def download_dewar_label(dewar_id: int, db: Session = Depends(get_db)):
         db.query(DewarModel)
         .options(
             joinedload(DewarModel.pucks).joinedload(PuckModel.samples),
-            joinedload(DewarModel.contact_person),
+            joinedload(DewarModel.contact),
             joinedload(DewarModel.return_address),
             joinedload(DewarModel.shipment),
         )