Add user manager page (#22)

Reviewed-on: #22

src/GameIdeas/GameIdeas.Shared/Dto/UserDto.cs

@@ -4,8 +4,8 @@ namespace GameIdeas.Shared.Dto;
 
 public class UserDto
 {
-    public int? Id { get; set; }
+    public string? Id { get; set; }
     public string? Username { get; set; }
     public string? Password { get; set; }
-    public string? RoleId { get; set; }
+    public RoleDto? Role { get; set; }
 }