[DPB|202012] Update Dynamic Port Breakout Logic for flexible alias support and related Test cases

[samaity]

Signed-off-by: Sangita Maity [email protected]

Why I did it

To fix DPB| wrong aliases for interfaces issue, implimented flexible alias support design doc

How I did it

1. Removed "alias_at_lanes" from port-configuration file(i.e. platfrom.json)
2. Added dictionary to "breakout_modes" values. This defines the breakout modes available on the platform for this parent port, and it maps to the alias list. The alias list presents the alias names for individual ports in order under this breakout mode.

{
    "interfaces": {
        "Ethernet0": {
            "index": "1,1,1,1",
            "lanes": "0,1,2,3",
            "breakout_modes": {
                "1x100G[40G]": ["Eth1"],
                "2x50G": ["Eth1/1", "Eth1/2"],
                "4x25G[10G]": ["Eth1/1", "Eth1/2", "Eth1/3", "Eth1/4"],
                "2x25G(2)+1x50G(2)": ["Eth1/1", "Eth1/2", "Eth1/3"],
                "1x50G(2)+2x25G(2)": ["Eth1/1", "Eth1/2", "Eth1/3"]
            }
        }
}

How to verify it

config interface breakout

Which release branch to backport (provide reason below if selected)

• 201811
• 201911
• 202006
• 202012

Description for the changelog

A picture of a cute animal (not mandatory but encouraged)