and rename to SvxBorderLineStyle

Change-Id: I19e530f162e4ca6290a0ad076e7fe3d5775ae6bc
Reviewed-on: https://gerrit.libreoffice.org/35265Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>