Read cpu and memory usage from cgroup files

[prathyushpv]

DO NOT MERGE: This PR is only for testing.

What was changed

Read CPU and memory usage from cgroup files.

Why?

Currently CPU and memory usage is read using the library github.com/shirou/gopsutil. This will return the usage values of the host machine if worker is running in containers. We have to read cgroup memory and cpu usage to get a container's memory usage.

Checklist

1. Closes

2. How was this tested:

3. Any docs updates needed?