fdo82708 Add missing tooltips to Writer Statusbar

Change-Id: Ie44b8de69b98ebfa789cc8f9a1d8a60b698fc154
Reviewed-on: https://gerrit.libreoffice.org/12368
Reviewed-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>
Tested-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>