No border attribute is a special case for vcl/TabControl, so by defualt
created with corresponding UNO interface tabs were invisible.
To create invisible tabs there is already "tabcontrolnotabs"(?)

Change-Id: I3cc9baef9106f6c3fb5688daadbb5844d2b2a008
Reviewed-on: https://gerrit.libreoffice.org/67188
Tested-by: Jenkins
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>
(cherry picked from commit 18f2e73f)
Reviewed-on: https://gerrit.libreoffice.org/67401