Support for remediation on single worker node configurations

[novasbc]

Existing code requires there to be at least one other peer worker node before remediation can occur, precluding SNR from remediating on a configuration with 3 control plane nodes + 1 worker node, which is a scenario that we support for bare minimum deployments.

[novasbc]

We have changes for this, preparing a PR. I noticed the requirement for additional unit tests. We had created a unit test for the configuration parameter, but not the actual functionality. We're looking into what setup we need to successfully run all the unit tests - as at present, existing unit tests fail due to what I presume are environmental differences.