Labels are set now depending on row/col as before/after and above/below
.uno:InsertColumnsBefore and .uno:InsertColumnsAfter are captioned Before/After

Change-Id: Ifb4f791b62e3c96f50d457c785b6f793deb4fce9
Reviewed-on: https://gerrit.libreoffice.org/60080
Tested-by: Jenkins
Reviewed-by: Olivier Hallot <olivier.hallot@libreoffice.org>