[FEATURE] Better process killing and response when custom engine server might be restarting

[stikkireddy]

• We should use psutil list all process for vllm, ray, sglang and kill them instead of trying to kill from the port. this can sometimes orphaned/zombie proccesses
• the health thread which is restarting the model should present the life cycle of the model in a file for other threads to provide detail to the requesting service. We may want to make this a 429 to make the requestor wait