CIDEVSA-486 - added alert config to agent launch

Added a column called "alerts" for instrument and platform agent instances in preload.  The value is a "simple dict" exactly like it is for driver config.  This config is put into the agent config under the key "aparam_alert_config" as per Edward's needs.

test_loader.py tests added to confirm preload behavior, IMS tests updated to confirm config behavior.  SMOKE tests pass.