Refactor dewar and sample handling; improve grid data binding

Updated Dewar and Sample schemas, added nested relationships, and adjusted API responses for better data handling. Simplified puck normalization, enhanced data grid logic in the frontend, and implemented a PUT endpoint for updating samples. Incremented backend version to 0.1.0a15 and added new HTTP request example.

backend/main.py

@@ -139,8 +139,8 @@ def on_startup():
             load_slots_data(db)
         else:  # dev or test environments
             print(f"{environment.capitalize()} environment: Regenerating database.")
-            Base.metadata.drop_all(bind=engine)
-            Base.metadata.create_all(bind=engine)
+            # Base.metadata.drop_all(bind=engine)
+            # Base.metadata.create_all(bind=engine)
             if environment == "dev":
                 from app.database import load_sample_data