Refactor AuthController to use MediatR

- Added using directive for DigitalData.Core.Abstraction.Application.DTO.
- Marked IUserService and GetUserWithClaims as obsolete.
- Transitioning towards MediatR for handling requests and responses.

DigitalData.UserManager.API/Controllers/AuthController.cs

@@ -2,10 +2,10 @@
 using Microsoft.AspNetCore.Authorization;
 using DigitalData.UserManager.Application.DTOs.Auth;
 using DigitalData.UserManager.Application.Contracts;
-using DigitalData.Core.DTO;
 using Microsoft.Extensions.Localization;
 using DigitalData.UserManager.Application;
 using System.Security.Claims;
+using DigitalData.Core.Abstraction.Application.DTO;
 
 namespace DigitalData.UserManager.API.Controllers;
 
@@ -14,9 +14,11 @@ namespace DigitalData.UserManager.API.Controllers;
 public class AuthController : ControllerBase
 {
     private readonly ILogger<UserController> _logger;
+    [Obsolete("Use MediatR")]
     private readonly IUserService _userService;
     private readonly IStringLocalizer<Resource> _localizer;
 
+    [Obsolete("Use MediatR")]
     public AuthController(ILogger<UserController> logger, IUserService userService, IStringLocalizer<Resource> localizer)
     {
         _logger = logger;
@@ -34,6 +36,7 @@ public class AuthController : ControllerBase
 
     [Authorize]
     [HttpGet("user")]
+    [Obsolete("Use MediatR")]
     public async Task<IActionResult> GetUserWithClaims()
     {
         try