feat: Lesevorgang für Benutzerprofil mittels MediatR und Repository implementiert

- ReadProfile-Request eingeführt, um Benutzerprofil anhand der UserId abzurufen
- ReadProfileHandler hinzugefügt, der das Profil aus dem IProfileRepository liest
- Asynchrone Verarbeitung mit Unterstützung für CancellationToken integriert

src/WorkFlow.Infrastructure/Repositories/ProfileRepository.cs

@@ -28,17 +28,18 @@ public class ProfileRepository : IProfileRepository
     /// Retrieves the <see cref="Profile"/> associated with a given user ID by calling a database function.
     /// </summary>
     /// <param name="userId">The unique identifier of the user whose profile is to be retrieved.</param>
+    /// <param name="cancel">Propagates notification that operations should be canceled.</param>
     /// <returns>
     /// A task that represents the asynchronous operation. The task result contains the <see cref="Profile"/> object if found; otherwise, <c>null</c>.
     /// </returns>
     /// <remarks>
     /// Logs an error if no profile is found, or if multiple profiles are returned, indicating potential data issues.
     /// </remarks>
-    public async Task<Profile?> ReadAsync(int userId)
+    public async Task<Profile?> ReadAsync(int userId, CancellationToken cancel = default)
     {
         var profiles = await _context.Profiles
             .FromSqlRaw("SELECT * FROM FNMWF_GET_PROFILES ({0})", userId)
-            .ToListAsync();
+            .ToListAsync(cancel);
 
         if (profiles == null || profiles.Count == 0)
         {