feat: Simplify function-to-executor pattern

Author: lokitoth

dotnet/samples/GettingStarted/Workflows/_Foundational/01_ExecutorsAndEdges/Program.cs

@@ -20,7 +20,9 @@ public static class Program
     private static async Task Main()
     {
         // Create the executors
-        UppercaseExecutor uppercase = new();
+        Func<string, string> uppercaseFunc = s => s.ToUpperInvariant();
+        var uppercase = uppercaseFunc.AsExecutor("UppercaseExecutor");
+
         ReverseTextExecutor reverse = new();
 
         // Build the workflow by connecting executors sequentially
@@ -40,23 +42,6 @@ private static async Task Main()
     }
 }
 
-/// <summary>
-/// First executor: converts input text to uppercase.
-/// </summary>
-internal sealed class UppercaseExecutor() : Executor<string, string>("UppercaseExecutor")
-{
-    /// <summary>
-    /// Processes the input message by converting it to uppercase.
-    /// </summary>
-    /// <param name="message">The input text to convert</param>
-    /// <param name="context">Workflow context for accessing workflow services and adding events</param>
-    /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests.
-    /// The default is <see cref="CancellationToken.None"/>.</param>
-    /// <returns>The input text converted to uppercase</returns>
-    public override ValueTask<string> HandleAsync(string message, IWorkflowContext context, CancellationToken cancellationToken = default) =>
-        ValueTask.FromResult(message.ToUpperInvariant()); // The return value will be sent as a message along an edge to subsequent executors
-}
-
 /// <summary>
 /// Second executor: reverses the input text and completes the workflow.
 /// </summary>