Frequently-used measurement fields such as classification and pixel flags should have shortened aliases that can be used instead of their full, package-qualified versions. In some cases, these may serve as a sort of slot (e.g. we may have multiple classifications algorithms someday).

In this issue, we should audit all current measurement algorithm fields that don't already have a slot that works for them and consider whether there should be a standard alias. We also need to work out a system for defining these aliases, probably in the config for SingleFrameMeasurementTask.