Clear session state before loading contest data in app.py

- Added logic to clear the session state when selecting a contest to load, ensuring a fresh start for data processing.
- Improved user experience by preventing potential conflicts with previously loaded contest data during uploads.

app.py

@@ -72,6 +72,7 @@ with tab1:
         st.info("Go ahead and upload a Contest file here. Only include player columns and an optional 'Stack' column if you are playing MLB.")
         if parse_type == 'DB Search':
             contest_name_var = st.selectbox("Select Contest to load", name_parse)
+            st.session_state.clear()
             if 'Contest_file' not in st.session_state:
                 if st.button('Load Contest Data', key='load_contest_data'):
                     st.session_state['Contest_file'] = grab_contest_data(sport_select, contest_name_var, contest_id_map, date_select)