Path alias generated for stub entities

@axicdv Thank you for this fix!

The fix idea looks good but we can avoid duplicating that code in so many places. The simplest way to do it, is to do that check and set the skip value right before saving the entity in ContentEntityStorageTrait::save(), in Multiversion module (before try/catch statement).

How the code should look:

     // We prohibit creation of the url alias for entities with a random label,
    // because this can lead to unnecessary redirects.
    if ($entity->_rev->is_stub && isset($entity->path->pathauto)) {
      $entity->path->pathauto = PathautoState::SKIP;
    }

Moving the issue to Multiversion.

Thanks!