Windup 210: Simplification of Classification and Hint

Not sure if you will like the classification simplification, it is quite hacky.
However, I seperated both simplification to two different commits.

Both of them are now able to use the "pass variableName from Iteration" simplification.
I didn't catch this before. I think these would make more sense to be in AbstractIterationOperation rather than in WindupOperationBuilder.