[TASK] Cleanup sys_workspace mentions in t3lib/stddb/tables.php

Change-Id: I358c131274c00efa60193f958c6f1e378eff9857
Resolves: #M17838
Resolves: #12616
Reviewed-on: http://review.typo3.org/991


Reviewed-by: Philipp Gampe <forge.typo3.org@philippgampe.info>
Reviewed-by: Susanne Moog <typo3@susannemoog.de>
Tested-by: Susanne Moog <typo3@susannemoog.de>
Reviewed-by: Ringer Georg <mail@ringerge.org>
Tested-by: Ringer Georg <mail@ringerge.org>
Reviewed-by: Andreas Wolf <andreas.wolf@ikt-werk.de>
Tested-by: Andreas Wolf <andreas.wolf@ikt-werk.de>