Add butterfly with embedded twiddle factor multiplication and update FFT function accordingly

When creating and FFT the user should be able to pick whether the butterflies should embed the twiddle factor multiplication.

The upper output of the butterfly might thus appear before the lower which should be reflected in the scheduling.

added Operations SFG GUI Scheduling labels

removed SFG GUI label

added SFG generators label

Should probably be done at the same time as #294 (closed)

mentioned in issue #294 (closed)