[vstest]Remove config calls from test_mclag_cfg.py in swss vs tests

[dgsudharsan]

Description

As a part of ongoing effort to decouple vstests from sonic-utilities, the click commands called in vs tests should be modified to redis-CLI based config_db set.
This is to remove vs tests from running in sonic-utilities pipeline checkers

Example of existing command in test_mclag_cfg:
https://github.com/Azure/sonic-swss/blob/00266891a9f41e5bd37100b05237e865cde429b2/tests/test_mclag_cfg.py#L75

Example of how to migrate:
sonic-net/sonic-swss#2179

Steps to reproduce the issue:

Describe the results you received:

Describe the results you expected:

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):

[dgsudharsan]

@Praveen-Brcm @adyeung Can you please look into this?

[prsunny]

@Praveen-Brcm , could you please address this? @gechiang for viz

[Praveen-Brcm]

@prsunny, @gechiang , @dgsudharsan : Am working on the changes and will have them in by this week.

[adyeung]

Fix ready at sonic-net/sonic-swss#2264