[!!!][TASK] Remove "content_doktypes"

The global option "content_doktypes" is
1. outdated (still contains doktypes 2 which was removed in 4.x)
2. only in use for Workspace Preview Links and Frontend Editing to query page trees

However, the idea was to disallow content editing (QuickEdit) and skip
search of other doktypes for simple DB search (removed in TYPO3 v7)

This is not the case anymore and nowadays a hidden feature which is only
10% implemented, and just another tedious option bloating the system.

The option has been removed and also cleaned via SilentConfigurationUpgradeService.

Resolves: #82803
Releases: master
Change-Id: I4ca868f721142d2ac9f1de0c1a7bccc33086989b
Reviewed-on: https://review.typo3.org/54438


Reviewed-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Tested-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>