Related fdo#80538 Re-adding toolbar separators

Change-Id: I29c2171495c0419fa5b6a7b99725d6098331afd0
Reviewed-on: https://gerrit.libreoffice.org/11523
Reviewed-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>
Tested-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>