Implement a Generic pkt Trapping infrastructure

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Implement a Generic pkt Trapping infrastructure.

Currently, pkt trap by application is supported based on protocol value in L2 and L3 hdr.
Protocol may wish to trap pkts based on other criteria, not necessary a protocol value. For ex, trapping all multicast pkts, or trapping pkts recvd on particular vlan.
Re-implement pkt trap infrastructure to meet this need.

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Committed.