[JIRA] (OVIRT-1523) Support multipile executors per CI stage (V2)

Support multipile executors per CI stage (V2) --------------------------------------------- Key: OVIRT-1523 URL: https://ovirt-jira.atlassian.net/browse/OVIRT-1523 Project: oVirt - virtualization made easy Issue Type: Improvement Components: oVirt CI Reporter: Barak Korren Assignee: infra Labels: standard-ci Currently we allow creating just one Jenkins "Free-Style" job per standard-CI stage and distribution. This means for e.g. that you can only have one "check-patch" script running on EL7 for a given project. It had been requested several times to allow having multiple standard-CI scripts running in parallel on separate slaves as a means to get CI results faster. Implementing this properly will probably require implementing both OVIRT-1522 and OVIRT-1013