Add ApiExplorerSettings to DTOs and update controllers

This commit introduces the `[ApiExplorerSettings(IgnoreApi = true)]` attribute to various DTO classes to exclude them from API documentation. The `using Microsoft.AspNetCore.Mvc;` directive has been added to several files to support ASP.NET Core MVC features.

Additionally, comments in `HistoryController.cs` have been reformatted for clarity, and `LocalizationController.cs` has been updated with standard API controller attributes. These changes improve code organization and maintain cleaner API documentation.

EnvelopeGenerator.Application/DTOs/Receiver/ReceiverCreateDto.cs

@@ -1,9 +1,11 @@
-using System.ComponentModel.DataAnnotations;
+using Microsoft.AspNetCore.Mvc;
+using System.ComponentModel.DataAnnotations;
 using System.Security.Cryptography;
 using System.Text;
 
 namespace EnvelopeGenerator.Application.DTOs.Receiver
 {
+    [ApiExplorerSettings(IgnoreApi = true)]
     public record ReceiverCreateDto([EmailAddress] string EmailAddress, string? TotpSecretkey = null)
     {
         public string Signature => sha256HexOfMail.Value;