Fix field cache for anonymous users by implementing a hook/listener

Problem/Motivation

There is still a problem with page_cache module, in the sence that it NEVER refreshed the cache, even if office_hours thinks it must be done in xx minutes, due to a opening/closing time.

A new option appears on the horizon.
- core\modules\toolbar\src\PageCache\AllowToolbarPath.php implements a service to influence that cacheability
Alternatively,
- core\lib\Drupal\Core\EventSubscriber\FinishResponseSubscriber.php is a Listener to an Event, that may also serve the same purpose.

Steps to reproduce

Proposed resolution

Implement one of above classes.

Remaining tasks

User interface changes

API changes

Data model changes