Introduce scope_types in tenant networks policy
Introduce scope_types in tenant networks policy

Appropriate scope_type for nova case:
- https://specs.openstack.org/openstack/nova-specs/specs/ussuri/approved/policy-defaults-refresh.html#scope

This commit introduce scope_type for tenant networks policies
as 'system' and 'project'.

Partial implement blueprint policy-defaults-refresh-deprecated-apis

Change-Id: I71a966d23f117595e42dd1afc1e10baece9b2a25

openstack/nova,mahak/nova,klmitch/nova,openstack/nova,mahak/nova,klmitch/nova,klmitch/nova,openstack/nova,klmitch/nova,mahak/nova