The command of 'openstack resource provider show <HOST1_UUID>' does not
return the uuid. This patch fixes it. Then following commands use
'host_id' instead of 'server_id'.
Change-Id: I60298ea3b22d9dfec2cd7a3e9950ed04aedc6bf5
Closes-Bug: #1853745
Added reference documentation and release note to explain how filtering
of hosts by isolate aggregates works.
Change-Id: I8d8086973039308f9041a36463a834b5275708e3
Implements: blueprint placement-req-filter-forbidden-aggregates