Enhance session state management in app.py for contest and projections files

- Updated logic to check for existing adjusted dataframes in session state before loading new files, preventing overwrites and ensuring data integrity.
- Improved clarity in the handling of contest and projections file uploads by incorporating checks for 'Adj_Contest' and 'Adj_projections_df' in session state.

app.py

@@ -35,7 +35,7 @@ with tab1:
         if 'Contest' in st.session_state:
             del st.session_state['Contest']
 
-        if Contest_file:
+        if Contest_file and 'Adj_Contest' not in st.session_state:
             st.session_state['Contest'], st.session_state['ownership_df'], st.session_state['actual_df'], st.session_state['entry_list'] = load_contest_file(Contest_file, sport_select)
             st.session_state['Contest'] = st.session_state['Contest'].dropna(how='all')
             st.session_state['Contest'] = st.session_state['Contest'].reset_index(drop=True)
@@ -66,7 +66,7 @@ with tab1:
                 mime="text/csv"
             )
             
-        if projections_file:
+        if projections_file and 'Adj_projections_df' not in st.session_state:
             export_projections, st.session_state['projections_df'] = load_file(projections_file)
             if st.session_state['projections_df'] is not None:
                 st.success('Projections file loaded successfully!')