Update delist and list recommender pages to include beta warning

- Added a beta warning message to both the delist and list recommender pages, informing users that the features are in beta and subject to change.
- Removed the obsolete `list_delist_recommender.py` file to streamline the codebase and avoid confusion.

Author: goldhaxx

src/page/delist_recommender.py

@@ -72,7 +72,7 @@ def delist_recommender_page():
     """
     st.title("📉 Delist Recommender")
     st.markdown("This page provides recommendations for delisting or adjusting leverage for Drift perpetual markets based on various metrics calculated by the backend.")
-
+    st.markdown("THIS PAGE IS IN BETA AND SUBJECT TO CHANGE. USE AT YOUR OWN RISK.")
     # Fetch data
     data = fetch_delist_recommendations()