EvictionRequest API

There are many issues with today's Eviction API and PodDisruptionBudgets that are of great concern to cluster administrators and application owners. These issues range from insufficient data safety, application availability, autoscaling to node draining issues. This KEP proposes to add a new declarative EvictionRequest and Eviction API to manage the eviction of pods. Its mission is to allow for a cooperative termination of a pod, usually in order to run the pod on another node. If the owner of the pod does not cooperate, the eviction request will try to resort to a pod eviction (API-initiated Eviction). These new APIs can be used to implement additional capabilities around node draining, pod descheduling, autoscaling, or as a general interface between applications and/or controllers. It would provide additional safety and observability guarantees and prevent bad practices as opposed to just using the current Eviction API endpoint and PodDisruptionBudgets.