Refactor Rec Actions handling with MediatR support

Refactored the handling of "Rec Actions" by introducing the `InvokeRecActionCommandHandler` class and leveraging the MediatR library for command handling. Simplified the logic in `InvokeBatchRecActionsCommand.cs` by delegating HTTP request handling to the `sender.Send` method, which now uses `InvokeRecActionCommand`.

Updated `InvokeRecActionCommand` to implement the `IRequest` interface, enabling MediatR pipeline compatibility. Added `InvokeRecActionCommandExtensions` for converting `RecActionDto` to `InvokeRecActionCommand`, improving readability.

Centralized HTTP request logic in the new `InvokeRecActionCommandHandler`, which validates `RestType`, sends HTTP requests, and logs warnings for invalid actions. Removed unused `using` directives and added necessary ones for MediatR and logging.

This refactoring improves modularity, testability, and maintainability by separating concerns and streamlining the code structure.

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

@@ -27,22 +27,7 @@ public class InvokeRecActionsCommandHandler(ISender sender, IHttpClientFactory c
             await semaphore.WaitAsync(cancel);
             try
             {
-                if (action.RestType is null)
-                {
-                    logger?.LogWarning(
-                       "Rec action could not be invoked because the RestType value is null. ProfileId: {ProfileId}, ActionId: {ActionId}",
-                       action.ProfileId,
-                       action.ActionId
-                   );
-                    return;
-                }
-
-                var method = new HttpMethod(action.RestType.ToUpper());
-                var msg = new HttpRequestMessage(method, action.EndpointUri);
-
-                var response = await http.SendAsync(msg, cancel);
-                var body = await response.Content.ReadAsStringAsync(cancel);
-                var headers = response.Headers.ToDictionary();
+              await sender.Send(action.ToInvokeCommand(), cancel);
             }
             catch(Exception ex)
             {