Adding snappi vlan traffic testcase (#5)

[selldinesh]

This PR contains the test cases for running l2 traffic using snappi and SAI api with data driven model

[chrispsommers]

Please see comments about test cases being able to run with SW or HW traffic generators, and avoiding vendor-specific settings if possible

[andriy-kokhan]

@selldinesh , as a common practice, a test should contain both setup and teardown.

It make sense to split setup and teardown into separate test-cases either in case the same basic configuration should be used by the number of tests (by test suite) or when we want to test some object removal as a separate scenario. In such case it's better to group the tests into the test class. E.g.,

SAI-Challenger/tests/ut/test_acl_ut.py

Line 21 in 53b32cc

class TestIngressACL:

Please correct me if I'm wrong but this PR contains neither of these two. It's more like a standalone VLAN scenario with traffic. Something very similar to

SAI-Challenger/tests/test_l2_basic.py

Line 20 in 53b32cc

def test_l2_access_to_access_vlan(npu, dataplane):

So, I'd suggest to make it as a single TC. Also, please make sure the teardown procedure reverts the configuration to what was right before TC execution.

[andriy-kokhan]

Please make sure this TC will we skipped in case ((pytest is executed without specifying the test file of or tests wildcard) and dataplane is not snappi).

[dks0692]

added the skip all fixture

[andriy-kokhan]

As I mentioned above, please make sure that the traffic related part of TC will be skipped in case dataplane type is not snappi.

if npu.run_traffic and dataplane.config["type"] == "snappi":
    # Traffic check