a quirk of the menutogglebutton is that in rollover it always gets drawn as if
its released, so refactor confusing stuff to take visual mode from a
DrawButtonFlags, allowing the dropping of DrawFlags::NoRollover

Change-Id: I14225bd0d2fbc8276a2b0a26c20673df0105891c
Reviewed-on: https://gerrit.libreoffice.org/53562Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>