Refactor GetOutput method in ActivityExtensions

The GetOutput method was extracted from the execution contexts to ensure more precise and isolated functionality. It was simplified and redefined in three contexts which are: the ActivityExecutionContext, the WorkflowExecutionContext, and the ExpressionExecutionContext. This will enhance maintainability and readability of the code.

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

@@ -58,21 +58,6 @@ public static IEnumerable<NamedOutput> GetOutputs(this IActivity activity)
 
  return query.Select(x => x!).ToList();
  }
-
- /// <summary>
- /// Gets the output with the specified name.
- /// </summary>
- /// <param name="activity">The activity to get the output from.</param>
- /// <param name="context">The workflow execution context.</param>
- /// <param name="outputName">Name of the output.</param>
- /// <returns>The output value.</returns>
- public static object? GetOutput(this IActivity activity, WorkflowExecutionContext context, string? outputName = default)
- {
- var workflowExecutionContext = context;
- var outputRegister = workflowExecutionContext.GetActivityOutputRegister();
- var output = outputRegister.FindOutputByActivityId(activity.Id, outputName);
- return output;
- }
 
  /// <summary>
  /// Gets the output with the specified name.
@@ -83,7 +68,10 @@ public static IEnumerable<NamedOutput> GetOutputs(this IActivity activity)
  /// <returns>The output value.</returns>
  public static object? GetOutput(this IActivity activity, ActivityExecutionContext context, string? outputName = default)
  {
- return activity.GetOutput(context.WorkflowExecutionContext, outputName);
+ var workflowExecutionContext = context.WorkflowExecutionContext;
+ var outputRegister = workflowExecutionContext.GetActivityOutputRegister();
+ var output = outputRegister.FindOutputByActivityInstanceId(context.Id, outputName);
+ return output;
  }
 
  /// <summary>
@@ -95,7 +83,12 @@ public static IEnumerable<NamedOutput> GetOutputs(this IActivity activity)
  /// <returns>The output value.</returns>
  public static object? GetOutput(this IActivity activity, ExpressionExecutionContext context, string? outputName = default)
  {
- return activity.GetOutput(context.GetWorkflowExecutionContext(), outputName);
+ var activityExecutionContext = context.GetActivityExecutionContext();
+
+ if (activityExecutionContext == null)
+ return null;
+
+ return activity.GetOutput(activityExecutionContext, outputName);
  }
 
  /// <summary>