DefaultContentEntityProcessor does not respect field access

Problem

From looking at the code, I think DefaultContentEntityProcessor does not respect field access .

Steps to reproduce

      foreach ($display->getComponents() as $field_name => $options) {
        if (isset($entity->{$field_name})) {
          $this->getCustomElementGenerator()->process($entity->get($field_name), $custom_element, $viewMode);
        }
      }

getComponents() does not have a field-access filter, nor is it filtered here. It's usuallly done at EntityViewDisplay::buildMultiple()

Proposed resolution

Check field access like

      foreach ($display->getComponents() as $field_name => $options) {
        if (isset($entity->{$field_name}) && field access) {
          $this->getCustomElementGenerator()->process($entity->get($field_name), $custom_element, $viewMode);
        }
      }

besides that we need to make sure to reflect this in caching metadata as done by EntityViewDisplay:

 // Apply the field access cacheability metadata to the render array.
          $this->renderer
            ->addCacheableDependency($build_list[$id][$name], $field_access);

Best, let's also add a follow-up for adding a unit test that ensures that not accessible fields are not displayed.