Changes from original tests:
- Adjust migrated imports and configuration.
- Replaced test UUIDs with unique ones.
- Configured devstack single-thread ovn job for feature.
- CLI prefix fetched using 'get_osp_cmd_prefix'.
- Adapted 'check_service_setting' parameters to whitebox method.
- Migrated and adjusted 'cli_create_resource' base method
for podified/devstack use.
This feature might be modified further soon, so more adjusts and tests
will be done on podified setups soon as well.
Feature isn't enabled in devstack gates, most code depends
on already merged functions or CLI, more relevant to have code merged in
repo for podified testing in other CI jobs.
Change-Id: I63c768b9ad352cb9809d94aa4743a7d5d00f0721
7c2b58eb67