QUADS Flask Web UI (Phase 2: Self-Service Scheduling)

[sadsfae]

This is an RFE for the second phase of the Flask UI for QUADS. Initially we'd extend a subset of machines that can be scheduled this way, perhaps with a host identifier or Foreman host parameter.

This is related to and depends on https://github.com/redhat-performance/quads/issues/86

[sadsfae]

TODO: Flesh out more implementation details here, to consider configurable thresholds that turn self-scheduling on/off lab-wide and by model depending on capacity per lab and capacity within a specific model.

We might look at a manager tool which queries these values and toggles this on/off as needed run on a cron interval.

Lastly we might consider an argparse to force self-scheduling on/off that overrides the tool setting based on capacity per-model and lab-wide percentages.