[TASK] Use non-extjs labels for select tree

Removes the last dependencies of SelectTree to ExtJS

Resolves: #77597
Releases: master
Change-Id: Ia56254bba5939625039c46689f7a71739087a5cc
Reviewed-on: https://review.typo3.org/49550


Tested-by: Bamboo TYPO3com <info@typo3.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Tymoteusz Motylewski <t.motylewski@gmail.com>
Tested-by: Tymoteusz Motylewski <t.motylewski@gmail.com>