vrf: T6602: verify supplied VRF name on all interface types

Only some (e.g. ethernet or wireguard) interfaces validate if the supplied VRF
actually exists. If this is not validated, one can pass an invalid VRF to the
system which generates an OSError exception.

To reproduce

set interfaces vxlan vxlan1 vni 1000
set interfaces vxlan vxlan1 remote 1.2.3.4
set interfaces vxlan vxlan1 vrf smoketest

results in

OSError: [Errno 255] failed to run command: ip link set dev vxlan1 master smoketest_mgmt

This commit adds the missing verify_vrf() call to the missing interface types
and an appropriate smoketest for all interfaces supporting VRF assignment.