[TASK] Add typehints for ElementBrowser usage via SOBE

The TreeViews access the controllers via the global SOBE.
This patch adds typehints to easily identify those usages.

Resolves: #69139
Releases: master
Change-Id: Ib280d4f9a2eeeb347893d1a9ab761760d993cac5
Reviewed-on: http://review.typo3.org/42691


Reviewed-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Tested-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Reviewed-by: Daniel Goerz <ervaude@gmail.com>
Tested-by: Daniel Goerz <ervaude@gmail.com>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>