Handle fed jobs when a cluster is removed from fed

When a non-origin cluster is removed:
- running jobs remain - fed_details removed so it can't call home.
- origin cluster removes tracking job for running jobs
- pending jobs are removed.
- pending srun/sallocs don't get notified.
- other clusters remove removed cluster from viable and active sibs

When an origin cluster is removed:
- all pending jobs are removed from all clusters that had job.
- pending srun/sallocs are notified of termination
- running jobs remain.