CI/CD: add C3I jobs to poll for master branch and PRs on Pagure
    
    Two Jenkins jobs are added to poll for master branch changes and new PRs
    on Pagure.
    
    As a temporary solution for triggering pipeline builds automatically
    when changes on master branch or pull-requests, polling is used before
    we eventually move to UMB-WebHook triggers.
    
    The 2 polling jobs are needed because
    
    1. to keep the logic of polling separated with dev-pipeline job, which
    could be triggered by UMB-WebHook eventually.
    2. Currently Jenkins requires a persist workspace to poll for wildcard branch names.
    dev-pipeline job runs Jenkins slaves as pods, which are discarded after
    job runs.
    3. We need to run dev-pipline for both pre-merge and post-merge
    workflows. Polling for PRs and the master branch in a single Jenkins job
    will *NOT* trigger a master branch build when a fast-forward merge happens to a PR.
    
    We can't move the Jenkinsfile to an external file otherwise Jenkins will
    also poll for the branch where Jenkins file is referenced.