Refactor FuturesBot and SpotBot to utilize ticker enum for candle retrieval

- Updated GetCurrentCandleForPositionClose method in both FuturesBot and SpotBot to parse the ticker parameter into an enum, enhancing type safety and clarity.
- Adjusted TradingBotBase to use the position's ticker for candle retrieval, ensuring consistency across trading bot implementations.

src/Managing.Application/Bots/TradingBotBase.cs

@@ -477,7 +477,7 @@ public abstract class TradingBotBase : ITradingBot
                 {
                     lastCandle = TradingBox.IsBacktestTrading(Config.TradingType)
                         ? LastCandle
-                        : await exchangeService.GetCandle(Account, Config.Ticker,
+                        : await exchangeService.GetCandle(Account, positionForSignal.Ticker,
                             DateTime.UtcNow);
                 });
 
@@ -1177,7 +1177,7 @@ public abstract class TradingBotBase : ITradingBot
     {
         if (Positions.ContainsKey(position.Identifier))
         {
-            Candle currentCandle = await GetCurrentCandleForPositionClose(Account, Config.Ticker.ToString());
+            Candle currentCandle = await GetCurrentCandleForPositionClose(Account, position.Ticker.ToString());
 
             // Try broker history reconciliation first
             var brokerHistoryReconciled = await ReconcileWithBrokerHistory(position, currentCandle);