fdo#78824: Avoid having two menu entries having the same accelarator.

Sort should have an 'S' as accelerator.  The other one can be auto-assigned.

Change-Id: I61e630c9b6d89658c65cca77333f1ad0a591e3ab
(cherry picked from commit 1d7c97a607615c3f176c9f553d1d011e4ee55c1d)
Reviewed-on: https://gerrit.libreoffice.org/9399
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>