Refactored response and request models to dto naming. Adjusted mapper naming

Moonlight.Shared/Http/Requests/Users/CreateUserDto.cs

@@ -0,0 +1,13 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace Moonlight.Shared.Http.Requests.Users;
+
+public class CreateUserDto
+{
+    [Required]
+    [MinLength(3)]
+    [MaxLength(32)]
+    public string Username { get; set; }
+
+    [Required] [EmailAddress] public string Email { get; set; }
+}