tdf#144609: numbering "None" should still show prefix/suffix
Unlike it was implemented in tdf#143605, prefix and suffix
should be displayed anyway, we do not display only numbers.
Moreover tdf#143605 did accidentally fix tdf#135164
in a invalid way. So this patch is also providing a better
fix for it: untittest is already created and failing without it.
Problem in tdf#135164 is inability to distingush missing level
text (bullet char in given case) and empty ("") one. In first
case we should use abstract level definition. In second - not.
Change-Id: Ica3a714d22de4d2f14ebbcb12f0e1311dbc9b801
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/122609
Tested-by: Jenkins
Reviewed-by: Vasily Melenchuk <vasily.melenchuk@cib.de>