tdf#87884: UnoControlTabPageModel is using tabs w/o WB_NOBORDER

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>

toolkit/source/awt/vclxtoolkit.cxx

@@ -1468,7 +1468,10 @@ vcl::Window* VCLXToolkit::ImplCreateWindow( VCLXWindow** ppNewComp,
                 if ( rDescriptor.WindowServiceName.equalsIgnoreAsciiCase(
                         "tabpagecontainer" ) )
                 {
-                    pNewWindow = VclPtr<TabControl>::Create( pParent, nWinBits );
+                    // TabControl has a special case for tabs without border: they are displayed
+                    // in a different way, so we need to ensure that this style is not set, so
+                    // we can guarantee normal tab behavior
+                    pNewWindow = VclPtr<TabControl>::Create( pParent, nWinBits & (~WB_NOBORDER));
                     *ppNewComp = new VCLXTabPageContainer;
                 }
                 else if ( aServiceName == "animatedimages" )