Disable jobs on newly pushed pipelines

[HartS]

When pushing a new pipeline, disable all jobs which don't have dependencies (in other words, the jobs which 'kick off' the pipeline). This prevents later jobs from running (disabling all jobs can take a really long time, as pipelines can have >40 jobs, and an individual request needs to be made to concourse to pause each one)

After initial jobs are paused, the pipeline will be unpaused

[viccuad]

This looks extremely useful, thanks!. I would like to merge this and recreate the pipelines completely.