feat: Create Auth DTOs for login and register

[annikaholmqvist94]

public record RegisterRequest(
@notblank String name,
@notblank @Email String email,
@notblank @SiZe(min = 8) String password
) {}

public record LoginRequest(
@notblank @Email String email,
@notblank String password
) {}

public record AuthResponse(
String token
) {}