Add GetAuthorizedUsersQuery and UsersController

Introduced the `GetAuthorizedUsersQuery` feature to retrieve
authorized users, including the query, result, metadata, and
handler implementation. The handler interacts with the
`IUserRepository` to fetch user data.

Added a new `UsersController` with an `[HttpGet("authorized")]`
endpoint to expose the query via a RESTful API. The endpoint
returns appropriate HTTP status codes (`200 OK`, `401
Unauthorized`, `500 Internal Server Error`) based on the
result metadata.

Included necessary `using` directives for MediatR, ASP.NET
Core, and application features.

src/core/DigitalData.TaskFlow.Application/Features/Users/Queries/GetAuthorizedUsersQuery.cs

@@ -0,0 +1,22 @@
+using DigitalData.TaskFlow.Application.Common.Interfaces;
+using MediatR;
+
+namespace DigitalData.TaskFlow.Application.Features.Users.Queries;
+
+public sealed record GetAuthorizedUsersQuery : IRequest<GetAuthorizedUsersResult>;
+
+public sealed record GetAuthorizedUsersResult(IEnumerable<GetAuthorizedUsersMeta> Meta, IEnumerable<int> Wisagids);
+
+public sealed record GetAuthorizedUsersMeta(int? Code, string Message);
+
+public sealed class GetAuthorizedUsersQueryHandler(IUserRepository repo) : IRequestHandler<GetAuthorizedUsersQuery, GetAuthorizedUsersResult>
+{
+    public async Task<GetAuthorizedUsersResult> Handle(GetAuthorizedUsersQuery request, CancellationToken cancellationToken)
+    {
+        var users = await repo.GetAuthorizedAsync(cancellationToken);
+
+        return new GetAuthorizedUsersResult(
+            Meta: [new GetAuthorizedUsersMeta(Code: 0, Message: "OK")],
+            Wisagids: users.Select(x => x.WisagId));
+    }
+}

src/presentation/DigitalData.TaskFlow.API/Controllers/UsersController.cs

@@ -0,0 +1,36 @@
+using DigitalData.TaskFlow.Application.Features.Users.Queries;
+using MediatR;
+using Microsoft.AspNetCore.Mvc;
+
+namespace DigitalData.TaskFlow.API.Controllers;
+
+/// <summary>
+/// 
+/// </summary>
+/// <param name="sender"></param>
+[ApiController]
+[Route("api/users")]
+public sealed class UsersController(ISender sender) : ControllerBase
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="cancellationToken"></param>
+    /// <returns></returns>
+    [HttpGet("authorized")]
+    [ProducesResponseType(typeof(GetAuthorizedUsersResult), StatusCodes.Status200OK)]
+    [ProducesResponseType(typeof(GetAuthorizedUsersResult), StatusCodes.Status401Unauthorized)]
+    [ProducesResponseType(typeof(GetAuthorizedUsersResult), StatusCodes.Status500InternalServerError)]
+    public async Task<IActionResult> GetAuthorizedAsync(CancellationToken cancellationToken)
+    {
+        var result = await sender.Send(new GetAuthorizedUsersQuery(), cancellationToken);
+        var code = result.Meta.FirstOrDefault()?.Code;
+
+        return code switch
+        {
+            0 => Ok(result),
+            4 => Unauthorized(result),
+            _ => StatusCode(StatusCodes.Status500InternalServerError, result)
+        };
+    }
+}