Add debug print statement for backtesting uploads in app.py

- Introduced a print statement to display the working dataframe entries labeled 'Backtesting_upload', aiding in debugging and data verification during development.
- This change enhances visibility into the data being processed, ensuring accurate handling of backtesting uploads.

app.py

@@ -260,6 +260,8 @@ with tab2:
         else:
             working_df = st.session_state['Contest'].copy()
         
+        print(working_df[working_df['BaseName'] == 'Backtesting_upload'])
+        
         # Pre-compute lookup arrays for vectorized operations
         team_map = st.session_state['map_dict']['team_map']
         salary_map = st.session_state['salary_dict']