[202012] Apply separated DSCP_TO_TC_MAP and TC_TO_QUEUE_MAP on dualtor

[bingwang-ms]

Why I did it

This PR is to backport #12730 into 202012 branch.
The PR is to apply separated DSCP_TO_TC_MAP and TC_TO_QUEUE_MAP to uplink ports on dualtor.
The traffic with DSCP 2 and DSCP 6 from T1 is treated as lossless traffic.

DSCP    TC    Queue
2      2     2
6      6     6

Traffic with DSCP 2 or DSCP 6 from downlink is still treated as lossy traffic as before.

How I did it

Define DSCP_TO_TC_MAP|AZURE_UPLINK and TC_TO_QUEUE_MAP|AZURE_UPLINK.

How to verify it

1. Verified by UT
2. Verified by coping the new template to a testbed, and rendering a config_db.json

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

• 201811
• 201911
• 202006
• 202012
• 202106
• 202111
• 202205

Description for the changelog

Apply separated DSCP_TO_TC_MAP and TC_TO_QUEUE_MAP to uplink ports on dualtor

Ensure to add label/tag for the feature raised. example - PR#2174 under sonic-utilities repo. where, Generic Config and Update feature has been labelled as GCU.

Link to config_db schema for YANG module changes

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