Add logging to WFP as it can be long running

src/hdx/location/wfp_exchangerates.py

@@ -1,3 +1,4 @@
+import logging
 from datetime import timezone
 from typing import Dict, List
 
@@ -11,6 +12,8 @@
 except ImportError:
     WfpApiToken = None
 
+logger = logging.getLogger(__name__)
+
 
 class WFPExchangeRates:
     """Obtain WFP official exchange rates. Requires WFP credentials amd
@@ -91,6 +94,7 @@ def get_historic_rates(
         """
         historic_rates = {}
         for currency in currencies:
+            logger.info(f"Getting WFP historic rates for {currency}")
             currency_historic_rates = self.get_currency_historic_rates(
                 currency
             )