SectionBundledPurger::invalidateTags not using sitename

[malcolmp]

All of the purgers should use the sitename if it is configured in order to only purge tags only on the specified domain. Ideally the used sitename should also be exposed in a way so that it can be filtered within the Section Kibana request logs.

[kepol]

Moved this to:

https://www.drupal.org/project/section_purge/issues/3241219

as we're going to be using that issue queue to create a new Drupal 9 release soon.