Resource Group Follow-on: Evaluate putting ClusterServerConfiguration in MAC public API

ClusterServerConfiguration was added in #3533 as part of MAC as a way to configure resource groups in the ITs. Evaluate whether or not, and how, it should be exposed in MACs public API.

Start by reviewing ClusterServerConfiguration and the MAC changes introduced in #3533. Determine whether exposing it in MAC's public API is appropriate and how that exposure should work; the issue is done when that API decision and its scope are established.

Written by the indexing model from the issue text.