Implement closing all positions

core/exchanges/common.py

@@ -16,3 +16,9 @@ def get_balance_hook(user_id, user_name, account_id, account_name, balance):
             "balance": balance,
         },
     )
+
+
+def convert_open_trades(open_trades):
+    """
+    Convert a list of open trades into a list of Trade-like objects.
+    """