This does two things, which are steps towards removing next-guards:
Make all existing observations protocol-qualified, in a subdirectory like observations/20/...
Update all tests to use hosts that at least have a protocol, taken from the Host::test_host path that recently gained an environment variable to control its protocol
This does two things, which are steps towards removing next-guards:
observations/20/...Host::test_hostpath that recently gained an environment variable to control its protocol