feature exchange rate update automation

Automated downloading exchange rates from HMRC and updating the database. Added function call to the console and form applications.

Also added a form to show the console output in form application.

src/bnhtrade.ComTypeLib/Account/Account.cs

@@ -54,8 +54,7 @@ namespace bnhtrade.ComTypeLib
         public int CurrencyExchangeRateInsert(ConnectionCredential sqlConnCred, int exchangeRateSource, string currencyCode,
                 [MarshalAs(UnmanagedType.Currency)] decimal currencyUnitsPerGbp, DateTime periodStart, DateTime periodEnd, bool checkOverride = false)
         {
-            return new Core.Logic.Account.Currency().CurrencyExchangeRateInsert(exchangeRateSource, currencyCode,
-                currencyUnitsPerGbp, periodStart, periodEnd, checkOverride);
+            throw new Exception("This function has been retired, now handled by nightly routines");
         }
     }