Clean up setup and teardown processes for k6 tests

Clean up setup and teardown processes for k6 tests

- rename cps-base.yml to docker-compose.yml to use minimum
  docker-compose commands efficiently
- rename confusing file names:
  - run-k6-tests.sh to k6-main.sh
  - run-all-tests.sh to execute-k6-scenarios.sh
  - ncmp-test-runner.js to scenarios-config.js
- cleanup teardown.sh
  - not only endurance but also kpi should remove all ONAP docker images
    since setup function always builds them!
  - Don't remove any other images (they don't belong ONAP) because it
    bring extra pulling time during the setup, and make the pipeline
slower.
  - combine relevant methods into one
- add cm avc event and v3 data node get metrics to metrics.csv file to
  prevent them commit always
- add missing import for crypto

Issue-ID: CPS-2861

Change-Id: If3d5cc8e33e5a5baa34834aaa178be7803dd5f7d
Signed-off-by: halil.cakal <halil.cakal@est.tech>