Perf YAML Cleanups

Depends on SERVER-49786

From sys-perf yaml:

1. Remove mark_idle invocations and
2. Switch run-dsi invocations to use subprocess.exec and no extensions
   1. kill the set lines; no dsienv.sh or setup-dsi-env.sh--kill in DSI (kill signal_processing_setup.sh from DSI while you're there)
   2. never any absolute paths or .py suffixes always just run-dsi command; kill bin/anaysis.py
3. Kill "write yml config" in favor of expansions.yml
4. "deploy cluster" calls run-dsi deploy-cluster
5. Do json.send as a post task
6. Kill useless/constant project_dir, platform, script_flags vars

For perf.yml:

1. call analysis through run-dsi
2. the killall_mci expansion doesn't exist so kill that from the pre/post steps; make the pkill scripts not ugly af