Clean up of get_cookie_domain and change check_or_set to update_or_set

* Move request.host inside get_cookie_domain function
* Change host variable name to domain to match function name and what is returned
* Catch specific exceptions to delete cookies with invalid uuid (ValueError), do nothing for missing cookies (TypeError), and otherwise extend the expiration of cookies
* Changed check_or_set to update_or_set since goal is to extend expiration