Adding status field to image location -- domain and APIs changes

Adding a status field to image's each location property, each location
status can be 'active', 'pending_delete' and 'deleted'.

Under location's status information Scrubber service can make cleanup
based on DB records also but not a dedicated queue-file for each image.

This is second part of this change which covered DB API, domain and REST
API.

Partially-Implements BP: image-location-status

Change-Id: I744679e2dadbaec099aef33d8c5a3fe4ecf96865
Signed-off-by: Zhi Yan Liu <zhiyanl@cn.ibm.com>
Merge "Adding status field to image location -- domain and APIs changes"