[FEATURE] Show user TSconfig in Configuration module

The configuration module gets a new entry showing the
user TSconfig of the currently logged in user.
Note it is not possible to show user TSconfig of a different
user this way, this array is thus basically restricted
to admin users.

Resolves: #85017
Releases: master
Change-Id: Ic078160b2da1f2f5e24f13f9ee9ee708bf9a267e
Reviewed-on: https://review.typo3.org/56971


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Jan Helke <typo3@helke.de>
Tested-by: Jan Helke <typo3@helke.de>
Tested-by: Sascha Maier <sam@amedick-sommer.de>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>