* provider/openstack: Detect Region for Importing Resources
This commit changes the way the OpenStack region is detected and set.
Any time a region is required, the region attribute will first be
checked. Next, the OS_REGION_NAME environment variable will be checked.
While schema.EnvDefaultFunc handles this same situation, it is not
applicable when importing resources.
* provider/openstack: No longer ignore region in importing tests
* provider/openstack: Network and Subnet Import Fixes
This commit fixes the OpenStack Network and Subnet resources so that
importing of those resources is successful.