Add Winston formatter to conform to ECS structure
Winston's ECS formatter does the bare minimum for formatting fields. When adapting old code that was pre-ECS, it results in nonconforming fields.
This patch reformats the Bunyan request log structure from service-template-node that is passed into Winston. It currently does not handle the Bunyan error log structure (I don't know if that also needs reformatting).
Bug: T383448