[Mux] Neighbor handling based on FDB entry

[prsunny]

What I did

1. Neighbor handling based on FDB entries. When a new neighbor is learnt, the code lookup FDB table to get the associated physical port and based on the mux status for the port, the neighbor is programmed as local or tunnel nexthop.
2. Log level/message revisited based on log observations from current deployments

Why I did it

How I verified it

Ethernet96 mux status is - Standby

show arp
Address       MacAddress         Iface            Vlan
------------  -----------------  ---------------  ------
192.168.0.101  00:00:11:22:33:45  Ethernet96       1000

Feb  6 02:48:21.931004 str2-7050cx3-acs-02 ERR swss#orchagent: :- getPort: Failed to get bridge port ID for FDB entry 00:00:11:22:33:55, rv:-5
Feb  6 02:48:21.931004 str2-7050cx3-acs-02 NOTICE swss#orchagent: :- getMuxPort: FDB entry not found: Vlan Vlan1000, mac 00:00:11:22:33:55
Feb  6 02:48:21.935757 str2-7050cx3-acs-02 NOTICE swss#orchagent: :- addNeighbor: Created neighbor ip 192.168.0.101, 00:00:11:22:33:55 on Vlan1000
Feb  6 02:48:21.937385 str2-7050cx3-acs-02 NOTICE swss#orchagent: :- addNextHop: Created next hop 192.168.0.101 on Vlan1000
Feb  6 02:48:21.938899 str2-7050cx3-acs-02 INFO swss#orchagent: :- update: Neigh 192.168.0.101 on Vlan1000, add 1, state 2
Feb  6 02:48:21.938899 str2-7050cx3-acs-02 NOTICE swss#orchagent: :- disableNeighbor: Neighbor disable request for 192.168.0.101 
Feb  6 02:48:21.940604 str2-7050cx3-acs-02 NOTICE swss#orchagent: :- removeNeighbor: Removed next hop 192.168.0.101 on Vlan1000
Feb  6 02:48:21.952963 str2-7050cx3-acs-02 NOTICE swss#orchagent: :- removeNeighbor: Removed neighbor 00:00:11:22:33:55 on Vlan1000
Feb  6 02:48:21.952989 str2-7050cx3-acs-02 INFO swss#orchagent: :- addTunnelRoute: Add tunnel route DB 'Vlan1000:192.168.0.101/32'
Feb  6 02:48:21.954947 str2-7050cx3-acs-02 NOTICE swss#orchagent: :- create_route: Created tunnel route to 192.168.0.101/32 

Details if related

[prsunny]

/AzurePipelines run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[prsunny]

retest vs please