[!!!][TASK] Remove deprecated functionality in DataHandler

The Permission handling within DataHandler has been migrated
into PagePermissionAssembler in TYPO3 v10.

All other previously deprecated code within DataHandler is also removed.

The following previously deprecated code is now removed:
* DataHandler->assemblePermissions()
* DataHandler->setTSconfigPermissions()
* DataHandler->process_uploads()
* DataHandler->pMap
* DataHandler->defaultPermissions

Resolves: #91480
Releases: master
Change-Id: Ia52dc8c2fa042458272b49608c5b318e19e73735
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64599


Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>