CLOUDSTACK-6810: Fix storage migration of a vm with volume on local was failing. When a plan
with hostid included was passed to the local storage pool allocator, it returned all the local
storage pools in the cluster, instead of just the local pool on the given host in the plan.
This was happening the search at a host level was happening only for data disk. Fixed this.
Additionally, the query to list the storage pools on a host was failing if the pool did have
tags. Fixed the query too.

CLOUDSTACK-6802: Fix for not being able to attach data disk on local. This issue gets fixed
with the above issue too. The query to list pools on a host was failing if there were no
tags on the storage pool.