UnifyCR runtime debugging/monitoring/profiling utility

[sandrain]

It is not easy to check the UnifyCR runtime status without using debugging tools and skills. it would be convenient to provide a utility program that provides:

1. current daemon status including the memory consumption across all nodes.
2. file system statistics, such as the number of files, space consumption, etc.
3. a small shell-like environment where a user can interactively explore the namespace (cd, ls, ...)
4. moving files between unifycr volume and any other mountpoint (e.g., /lustre, /mnt/xfs, ...)

It has been discussed previously to include this feature in future.