Fix cluster resize
Fix cluster resize

There are two fixes included in this patch:

1. List nodes correctly. We have renamed minion to node, which
   cause the filter doesn't work correctly.
2. The response from magnumclient resize method is not a json,
   so we need to convert it to dict before return. Rolling upgrade
   has the same issue.

Task: 39810
Story: 2007697

Change-Id: I7a03dfea2c84a423f15cfbe4194a8492f72dbd35

openstack/magnum-ui,openstack/magnum-ui,openstack/magnum-ui,openstack/magnum-ui