Fix "prev" link pagination for instances with identical timestamps
This patch resolves an issue with the "prev" link when instances
have identical "created_at" values. This can occur when creating
instance using the "min/max count" option. The reverse sort does not
work correctly as the server list returned from nova is not an exact
reverse as the forward sort. It looks like the combination of sort_keys
must be unique to ensure the forward and reverse pagination properly.
As a workaround 'uuid' (server ID) is added to 'sort_keys'.
In addition, 'display_name' is added before 'uuid' in 'sort_keys'
to list servers in the alphabetical order (which sounds natural).
(cherry picked from commit