- Best Effort Policy: Return hint with nil affinity as opposed to
defaultAffinity when provider has no preference for NUMA affinty or no
possible NUMA affinities.
- Single NUMA Node Policy: Remove defaultHint from mergeProvidersHints.
Instead return appropriate TopologyHint where required.
- Update unit tests to reflect changes. Some test cases moved into
individual policy test functions due to differing returned affinties
per policy.