- ReflectometryILLPreprocess doesn't sum anymore.
- ReflectometryILLReduction is gone.
The functionality has been moved to two new algorithms:
- Summing (in lambda only for the moment) and reflectivity are calculated in ReflectometryILLSumForeground.
- Conversion from wavelength to momentum transfer is done in ReflectometryILLConvertToQ.

Re #20359