Optimize output retrieval by activityId and activityInstanceId

Modified `ActivityOutputRegister.cs` to utilize `LastOrDefault` instead of `FirstOrDefault` for retrieving the latest output by activityId or activityInstanceId. Now, in `ActivityExtensions.cs`, it differentiates between the output retrieval method based on whether the current activity context is identical to the requested one.

src/modules/Elsa.Workflows.Core/Extensions/ActivityExtensions.cs

@@ -70,8 +70,13 @@ from outputProp in outputProps
  {
  var workflowExecutionContext = context.WorkflowExecutionContext;
  var outputRegister = workflowExecutionContext.GetActivityOutputRegister();
- var output = outputRegister.FindOutputByActivityInstanceId(context.Id, outputName);
- return output;
+
+ // If the provided activity execution context is the same as the current activity's execution context, we return the exact output value of the current activity execution context.
+ if(context.Activity.NodeId == activity.NodeId)
+ return outputRegister.FindOutputByActivityInstanceId(context.Id, outputName);
+
+ // If the provided activity execution context is different from the current activity's execution context, we look for the last output value of the activity.
+ return outputRegister.FindOutputByActivityId(activity.Id, outputName);
  }
 
  /// <summary>

src/modules/Elsa.Workflows.Core/Models/ActivityOutputRegister.cs

@@ -61,7 +61,7 @@ public void Record(ActivityExecutionContext activityExecutionContext, string? ou
  /// <returns>The output value.</returns>
  public object? FindOutputByActivityId(string activityId, string? outputName = default)
  {
- var record = _records.FirstOrDefault(x => x.ActivityId == activityId && x.OutputName == (outputName ?? DefaultOutputName));
+ var record = _records.LastOrDefault(x => x.ActivityId == activityId && x.OutputName == (outputName ?? DefaultOutputName));
  return record?.Value;
  }
 
@@ -73,7 +73,7 @@ public void Record(ActivityExecutionContext activityExecutionContext, string? ou
  /// <returns>The output value.</returns>
  public object? FindOutputByActivityInstanceId(string activityInstanceId, string? outputName = default)
  {
- var record = _records.FirstOrDefault(x => x.ActivityInstanceId == activityInstanceId && x.OutputName == (outputName ?? DefaultOutputName));
+ var record = _records.LastOrDefault(x => x.ActivityInstanceId == activityInstanceId && x.OutputName == (outputName ?? DefaultOutputName));
  return record?.Value;
  }
 }