Revert "[TASK] Massive performance improvement for page tree"

Revert "[TASK] Massive performance improvement for page tree"

This patch needs to be reverted, because of a regression with
the page tree and the double click behavior.

Releases: master
Resolves: #66912
Resolves: #67322
Reverts: #63591

This reverts commit a89d3765663c0ed05c8435ad767f106fa9d60bf8.

Change-Id: I35b9d80f25fa1f2f3951bf70bbbe9e02dafdc28d
Reviewed-on: http://review.typo3.org/40154
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Frank Nägler <frank.naegler@typo3.org>
Tested-by: Frank Nägler <frank.naegler@typo3.org>