i18n for the Neutron Stadium

• Refer to oslo_i18n documentation for the general mechanisms that should be used: https://docs.openstack.org/oslo.i18n/latest/user/usage.html

• Each stadium project should NOT consume _i18n module from neutron-lib or neutron.

• It is recommended that you create a {package_name}/_i18n.py file in your repo, and use that. Your localization strings will also live in your repo.