Add BacktestSpotBot and update BacktestExecutor for spot trading support

- Introduced BacktestSpotBot class to handle backtesting for spot trading scenarios.
- Updated BacktestExecutor to support both BacktestFutures and BacktestSpot trading types.
- Enhanced error handling to provide clearer messages for unsupported trading types.
- Registered new command handlers for OpenSpotPositionRequest and CloseSpotPositionCommand in ApiBootstrap.
- Added unit tests for executing backtests with spot trading configurations, ensuring correct behavior and metrics validation.

src/Managing.Common/Enums.cs

@@ -620,6 +620,11 @@ public static class Enums
         /// <summary>
         /// Backtest futures trading mode
         /// </summary>
-        BacktestFutures
+        BacktestFutures,
+
+        /// <summary>
+        /// Backtest spot trading mode
+        /// </summary>
+        BacktestSpot
     }
 }