Restructure Object Storage chapter of Cloud Admin Guide

Restores Troubleshoot Object Storage
Removes Monitoring section, which was based on a blog

backport: havana
Closes-Bug: #1251515
author: nermina miller

Change-Id: I580b077a0124d7cd54dced6c0d340e05d5d5f983
Merge "Restructure Object Storage chapter of Cloud Admin Guide"