[tests/functional] - Add functional test case covering SCK-SOCK migration

[VihasMakwana]

Description: Add a new test case that covers no duplicates scenario during migration from SCK to SOCK

NOTE: This case will currently fail. It will become green once signalfx/splunk-otel-collector#3879 gets released

[rmfitzpatrick]

@atoulme, will these fixture changes break the implicit upgrade check added by #1051?

[jvoravong]

To get the EKS functional-tests up and running, you will have to close this PR and open up a different PR in a specific way due to recent project test updates. The EKS functional tests need to run with credentials that are only available in this repo.

• Create your feature branch in the https://github.com/signalfx/splunk-otel-collector-chart repo and not your personal fork.
• Create the PR with the feature branch in the https://github.com/signalfx/splunk-otel-collector-chart repo against the main branch.

[atoulme]

This PR has conflicts and is open from a fork, this won't work with our test checks. Going to close and reopen from this repository.