Also add item bits change notification function
for SalMenu to properly convert regenerated menu items
to check or radiocheck items.

Change-Id: I61f16a771b484644bbefd9afaf2776232d38a2f9
Reviewed-on: https://gerrit.libreoffice.org/68438
Tested-by: Jenkins
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>