SamplingCEMethodEnum (used by internalQuerySamplingCEMethod knob) only includes chunk and random sampling, while SamplingTechniqueEnum contains all the possible actual sampling methods (chunk, random, full coll scan, sequential scan, and strides) including the test-only methods.

This is increasingly confusing to work with, so we should either decide on different naming that better describes why there are two separate groups, or somehow unify these into one enum that includes everything we need.

Ideally also consider consolidating all of the sampling method related knobs into this one so that we don't need to keep separate knobs for sequentialScan or strides anymore either, but there might be some work required to figure out how to do that while maintaining sequentialScan and strides as test-only methods.