Closes-Bug: #1399014
Adding support to display pool info for OSDs

Fix:
    1. Added new column - Pool, to storage node disk details
    2. pool name constants DEFAULT, HDD, SSD added with their crush name mapping

Test:
    1. checked in UI and verified new Pool column in the storage node disk grid
    2. checked for default, ssd, and hdd api cursh names

Change-Id: I39ca0fe25590139c2a2b86142d76b518b45d6404
Merge "Closes-Bug: #1399014 Adding support to display pool info for OSDs"