Enhance filter reset functionality in app.py

- Updated the filter reset logic to include 'filter_form' in the preserved session state keys, ensuring that the filter form remains intact during resets.
- This change improves user experience by maintaining the state of the filter form while allowing other session keys to be cleared.

app.py

@@ -273,7 +273,7 @@ with tab2:
             with reset_col:
                 if st.button('Reset filters', key='reset4'):
                     for key in st.session_state.keys():
-                        if key not in ['Contest', 'Contest_file', 'Contest_upload', 'player_info', 'info_maps']:
+                        if key not in ['Contest', 'Contest_file', 'Contest_upload', 'player_info', 'info_maps', 'filter_form']:
                             del st.session_state[key]
 
             with st.form(key='filter_form'):