Directly connected routes

[taitov]

Add support directly connected routes.
Lookup neighbor MAC address by destination IP address (instead nexthop address).

[taitov]

Example config: https://github.com/yanet-platform/yanet/blob/main/autotest/units/001_one_port/071_route_directly_connected/controlplane.conf

{
  "modules": {
    "route0": {
      "type": "route",
      "interfaces": {
        "kni0.100": {
          "ipAddresses": [
            "10.10.0.1/24", ///< directly connected
            "2000:100::1/96" ///< directly connected
          ],
...

And check fib:

$ yanet-cli route lookup route0 10.10.0.100
ingress_physical_ports  prefix        nexthop  egress_interface  labels
----------------------  ------------  -------  ----------------  ------
kni0                    10.10.0.0/24           kni0.100          

$ yanet-cli route lookup route0 2000:100::100
ingress_physical_ports  prefix         nexthop  egress_interface  labels
----------------------  -------------  -------  ----------------  ------
kni0                    2000:100::/96           kni0.100