Implement QoS controller

This is a component of the slave that informs the slave about the possible "corrections" that need to be performed (e.g., shutdown container using recoverable resources).

This needs to be integrated with the resource monitor.

Need to figure out the metrics used for sending corrections (e.g., scheduling latency, usage, informed by executor/scheduler)

We also need to figure out the feedback loop between the QoS controller and the Resource Estimator.

class QoSController {
public:
  QoSController(ResourceMonitor* monitor);

  process::Queue<QoSCorrection> correction();
};