More flexibility in choosing static vs dynamic config in integration tests

In discussion on #6214, @alyssawilk outlined a nice redesign of the integration testing framework's interaction with configs. Here are the relevant comments:

I'm hoping by end of year the integration test framework will just let you live load any component as we can in prod

I'd like to have config booleans for static vs dynamic for all the DSes. So if they were all false, we'd get what we have today, and if they were all true we'd have what is described above, and whatever section is true has the hard-coded configuration swapped out for the discovery service config.

This issue will track that work.