InventoryPlugin should not update JobScheduler Objects when JobScheduler is stopping

Current Situation
When the JobScheduler is stopping it sends FileBasedRemoveEvents for all detached Items. Depending on the point in time when the plugin onClose method is called the Plugin sometimes updates all items based on the events.

Desired Behavior
When the JobScheduler is stopping the InventoryPlugin should react on the SchedulerStateChangedEvent and not perform any additional operations.