This MR mirrors the existing v4 RADIUS test cases under a single parameterized test for v6. Having all the tested scenarios in one place makes it easier to integrate RADIUS tests with HA which is the subject of another MR. This single parametrized test also has working code for v4 which could replace the existing tests, but I have not replaced them because I'm not sure that is what we want. Opinions are welcome.
The existing test cases required that we are able to retrieve leases rather than asserting that they have a certain value as is with most other tests. As a result, I needed to modify get_address6() to return v6 leases just as get_address4() does.
I also made a change to get_address4() to return the leases obtained from the ACK when it is available. These are the committed leases that a client ends up using. I think it's important to check for those. This is opposed to the previous situation where the transient leases returned in the OFFER were checked.
All the tests pass indicating that RADIUS works with v6.