[feat][core] common utils for kaas per-commit testing

- Determine scope of test suite against per-commit KaaS deployment based on keywords
written in gerrit commit body
- Determine if custom si tests/pipelines refspec forwarded from gerrit change request

Change-Id: I1fcd62c5374c3d7a0c9cccebed436541b005fd27
us: https://mirantis.jira.com/browse/PRODX-4282
1 file changed