Get container stats based on resource usage

This endpoint returns a live stream of a container’s resource usage statistics.

The precpu_stats is the CPU statistic of last read, which is used for calculating the CPU usage percentage. It is not the same as the cpu_stats field.

If either precpu_stats.online_cpus or cpu_stats.online_cpus is nil then for compatibility with older daemons the length of the corresponding cpu_usage.percpu_usage array should be used.