Adjust agent ping frequency by org and queue

We have a number of queues in our system to accommodate different build types. Some of these queues are only listened on by a small number of agents (one or two). These agents currently have their ping frequencies adjusted by the buildkite service based on the total number of agents in the organization. So in our case, even though there might be only one agent listening on a particular queue, it still gets a 10s ping interval from the service because of all of the agents listening on other queues in the organization.

This makes these smaller agent pools less responsive due to the larger ping interval.

It would be nice to have the ping interval determination take into account <organization, queues> so that small agent pools that listen on a particular queue can pick up jobs faster, as the other agents in the organization do not listen on that queue and will not be picking up its jobs.