[New Scheduler] Scheduling Decision Maker Does Not Include Paused Containers In Count

The scheduling decision maker receives `QueueSnapshot` which passes in `existingContainerNumByNamespace` value of the `ContainerCounter` class. However this class only watches for live containers in etcd under the `whisk/namespace/${namespace}` prefix, but not containers that are marked `warmed` under `whisk/warmed/${namespace}` or otherwise known as paused in docker. It's common for action containers to go paused, this can lead to namespace overprovisioning up to double beyond the namespace concurrency limit if a burst of traffic comes when namespace limit is reached and all containers are paused, and suboptimal decision making for over creating containers. @style95