Update OpenPositionCommandHandler and OpenSpotPositionCommandHandler to use consistent quantity for TakeProfit trades

- Modified the TakeProfit trade quantity assignment in both handlers to use position.Open.Quantity instead of the previously used quantity variable, ensuring consistency with StopLoss trades.

src/Managing.Application/Trading/Handlers/OpenPositionCommandHandler.cs

@@ -123,7 +123,7 @@ namespace Managing.Application.Trading.Handlers
             position.TakeProfit1 = exchangeService.BuildEmptyTrade(
                 request.Ticker,
                 takeProfitPrice,
-                quantity,
+                position.Open.Quantity, // Use same quantity as StopLoss for consistency
                 closeDirection,
                 request.MoneyManagement.Leverage,
                 TradeType.TakeProfit,

src/Managing.Application/Trading/Handlers/OpenSpotPositionCommandHandler.cs

@@ -121,7 +121,7 @@ public class OpenSpotPositionCommandHandler(
         position.TakeProfit1 = exchangeService.BuildEmptyTrade(
             request.Ticker,
             takeProfitPrice,
-            quantity,
+            position.Open.Quantity, // Use same quantity as StopLoss for consistency
             TradeDirection.Short,
             1, // Spot trading has no leverage
             TradeType.TakeProfit,