like expert configuration change the gear menu not to display a down indicator

and use CommandEvent to distinguish mouse/non-mouse context menus

Change-Id: I64bb660a9c7dacb5b90b240d9d76d29324c5fd9f
Reviewed-on: https://gerrit.libreoffice.org/69893
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>