feat: enhance e2e tests

[sitaram-kalluri]

- What I did

• Enhance the e2e tests as follows:
  • end2end_tests to run between the servers running on trunk branch - @ cicd1 and @ cicd2 (this is already in-place)
  • end2end_test_14 to run between the server trunk branch and server running on canary. - @ cicd1 and @ cicd4 for verifying the backward compatibility.
  • Move the step that updates the secondary images to as separate jobs that run's before the above two jobs.

- How I did it

• Refactor the at_client_sdk.yaml
• Rename config.yaml to config12.yaml in at_ene2end_tests package
• Add config14.yaml in at_ene2end_tests package

- How to verify it

- Description for the changelog