Currently the "sbeCompatible" and "sbeGroupCompatible" flags are used to check whether the expressions and accumulators are supported in SBE. The values are of boolean type, but we really have three levels of support in SBE, given that some SBE-compatible features are not enabled if "featureFlagSbeFull" is not enabled. So we should change that value to an enum.

Alternatively, we could set the "sbeCompatible" flag to false if the "featureFlagSbeFull" is false. But that's slightly hacky, and we would need to scatter the check of "featureFlagSbeFull" in multiple places. Capture the real level of compatibility seems appropriate.