Generate S(Q) button to do reverse transform from reciprocal -> real space

[marshallmcdonnell]

Need a button just like Generate G(r) but instead a Generate S(Q) to do the back transform. The interface should be simpler than the G(r) one, though. Here is an example sketch:

We currently work off the PDFFourierTransform algorithm, shown below:

The algorithm documentation is here:
http://docs.mantidproject.org/nightly/algorithms/PDFFourierTransform-v1.html

The code on GitHub is located here:
https://github.com/mantidproject/mantid/blob/abf4be6d7bddce52a0d0949f53eff5e8159e0abb/Framework/Algorithms/src/PDFFourierTransform.cpp

Do we need write a new Mantid algorithm (SQFourierTransform) or do we need to work with the current one? I think the former is better since PDFFourierTransform is used by others besides us (Dynamic PDF is one example looking at the Mantid repository)
The

[marshallmcdonnell]

Big push for this: We will be able to apply Fourier Filters in the Calculate G(r) Tab.

[marshallmcdonnell]

WIP is in the pystog repo. If we can do the following, this can be implemented for the GUI simply by calling Mantid algorithms:

• Close this issue in PyStoG repo related to differences in transforms: Comparing to Mantid PDFFourierTransform  pystog#26
• Create the algorithms in Mantid similar to how we did the converters ( PDConvertReciprocalSpace and PDConvertRealSpace

Then, calling these new algorithsm for the Reciprocal -> Real space can be implemented for the back transform

[marshallmcdonnell]

Based on discussion with @Kvieta1990 and Matt Tucker, will put this in backlog, not an important feature.