Remove obsolete attribute and add exception using directive

Removed [Obsolete] from ExceptionHandlingMiddleware, indicating it is no longer deprecated. Added using directive for ReC.Application.Common.Exceptions to support updated exception handling.

src/ReC.API/Middleware/ExceptionHandlingMiddleware.cs

@@ -7,13 +7,11 @@ using System.Text.Json;
 
 namespace ReC.API.Middleware;
 
-//TODO: Fix and use DigitalData.Core.Exceptions.Middleware
 /// <summary>
 /// Middleware for handling exceptions globally in the application.
 /// Captures exceptions thrown during the request pipeline execution,
 /// logs them, and returns an appropriate HTTP response with a JSON error details.
 /// </summary>
-[Obsolete("Use DigitalData.Core.Exceptions.Middleware")]
 public class ExceptionHandlingMiddleware
 {
     private readonly RequestDelegate _next;