[yang] Need Yang for DEVICE_NEIGHBOR_METADATA table

[ganglyu]

Description

We don't have Yang model for DEVICE_NEIGHBOR_METADATA table.

Steps to reproduce the issue:

1. Run 'config apply-patch' command
2. We can get below info:
   sonic_yang(6):Note: Below table(s) have no YANG models: CONSOLE_SWITCH, DEVICE_NEIGHBOR_METADATA, DHCP_SERVER, KDUMP, RESTAPI, SNMP, SNMP_COMMUNITY, TELEMETRY

Describe the results you received:

sonic_yang reports no Yang models.

Describe the results you expected:

sonic_yang reports no Yang models.

Output of show version:

(paste your output here)

Output of show techsupport:

(paste your output here or download and attach the file here )

Additional information you deem important (e.g. issue happens only occasionally):

[zhangyanzhao]

@StormLiangMS please help to create YANG model

[zhangyanzhao]

@StormLiangMS a kind reminder

[StormLiangMS]

Start to work on this, and ETA would be end of Aug'2022