[BUGFIX] t3editor: Add code autocompletion for listNum

Add code autocompletion for property listNum and property
preIfEmptyListNum in t3editor.

Resolves: #25732
Releases: master, 6.2
Change-Id: I13c15e2e262a926e8444d7f50933823b27cdcd9d
Reviewed-on: http://review.typo3.org/36793


Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>