Refactor HTTP requests to enable parallel execution

Replaced sequential `foreach` loop with LINQ's `Select` to create a collection of tasks for sending HTTP requests asynchronously. Added `Task.WhenAll` to execute all requests concurrently, improving performance. Removed the old `foreach` implementation in favor of a functional programming approach.

src/ReC.Application/RecActions/Commands/InvokeRecActionCommand.cs

@@ -21,7 +21,7 @@ public class InvokeRecActionCommandHandler(ISender sender, IHttpClientFactory cl
 
         var http = clientFactory.CreateClient();
 
-        foreach (var action in actions)
+        var tasks = actions.Select(async action =>
         {
             var method = new HttpMethod(action.RestType.ToUpper());
             var msg = new HttpRequestMessage(method, action.EndpointUri);
@@ -29,6 +29,8 @@ public class InvokeRecActionCommandHandler(ISender sender, IHttpClientFactory cl
             var response = await http.SendAsync(msg, cancel);
             var body = await response.Content.ReadAsStringAsync(cancel);
             var headers = response.Headers.ToDictionary();
-        }
+        });
+
+        await Task.WhenAll(tasks);
     }
 }