Set logged in user id when successful login

src/login.py

@@ -79,6 +79,7 @@ def check_password():
                     password,
                 ):
                     st.session_state["password_correct"] = True
+                    st.session_state["logged_in_user"] = user_id
                     del st.session_state["password"]  # Don't store the email or password.
                     del st.session_state["email"]
                     del password