Maintain backwards compatibility with 8.x-1.x action hooks and improve hook log messages

Problem/Motivation

The publish and unpublish processing in Scheduler 8.x-1.x contained an extra "unnecessary" call to $node->save() which has now been removed in 2.x. However, if 3rd-party modules have implemented the old hook_scheduler_publish_action and hook_scheduler_unpublish_action functions, these would not have needed to include a save, due to the extra one in Scheduler.

Proposed resolution

Therefore if processing has been done by one of these lagacy hooks, it would be safe to add back the save() so that the 3rd-party functionality continues to work without requiring as save() to be added in the hook implementaion.