provider/openstack: Adding all_metadata attribute (#13061)
provider/openstack: Adding all_metadata attribute (#13061)

This commit adds the all_metadata attribute which contains all
instance metadata returned from the OpenStack Compute API. This
is useful for gaining access to metadata which was applied
out of band of Terraform.

This commit also stops setting the original metadata attribute,
effectively making metadata an input and all_metadata the output
to reference all data from.
haxorof/terraform-provider-openstack,haxorof/terraform-provider-openstack,haxorof/terraform-provider-openstack