When using Command Controllers as scheduled tasks the Extbase
Scheduled Task is serialized. Some singleton properties like
'objectManager', 'commandManager' and 'taskExecutor' are serialized
leading to duplicates of this objects.

Added magic "__sleep" and "__wakeup" methods destructing and
re-constructing the above objects.

Resolves: #50723
Releases: 6.2, 6.1, 6.0
Change-Id: I0a84487a1d8885f75dd4b4eaf004bb0dc93645c2
Reviewed-on: https://review.typo3.org/23634
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
Reviewed-by: Philipp Gampe
Reviewed-by: Stefan Neufeind
Tested-by: Stefan Neufeind