[ovs/dpdk] Add opnfv.route_wrapper sls

[ovs/dpdk] Add opnfv.route_wrapper sls

- fix `route-br-ex` if-up.d script failing when route already exists
  by adding a wrapper around distro's '/sbin/route' binary in
  '/usr/local/sbin/route', exploiting default order in Ubuntu PATH;
- fix 'br-prv' duplicate entry in 'interfaces.d/ifcfg-br-prv' and
  'interfaces' caused by upstream bug [1];
- add barrier waiting for all baremetal nodes online before attempting
  reboot, trying to catch rare failures which are undetectable in logs
  as both a succesful reboot and a disconneted minion report 'n/c';

With the above in place, networking service should no longer fail
to start on cmp nodes w/ DPDK.

[1] https://github.com/saltstack/salt/issues/40262

Change-Id: I6d4895376ce323c14c997e6c9af2ea3eeeee0184
Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>