Remove the LogicException in ComponentTreeLoader that forces XB to only work with article nodes

Alternative approach: if we don't want to remove the exception outright, another option that will work for us is to remove this from ContentTemplateAwareViewBuilder:

      try {
        $this->componentTreeLoader->getXbFieldName($entity);
      }
      catch (\LogicException) {
        // This entity isn't opted into XB, so there's nothing else to do.
        continue;
      }

This would mean we don't care if any entity is "opted into" XB or not -- only that a template exists. However, we'd certainly want to restore this logic, or equivalent logic, at a later time.

The only difference that this MR brings is the exception logged in the database and is step forward and we would have to delete this sooner or later. I'm OK with this.

I've fixed one phpunit test and all should be green now.