Split out vtkTableFFT from Imaging/Fourier into Filters/Fourier

This causes a cycle in kits because vtkFiltersStatistics (of the vtkFilters kit) requires vtkTableFFT (of the vtkImaging kit), but the vtkImaging kit requires vtkFilters in many places. Currently, vtkTableFFT is implemented as running an FFT over the table by shoving the data into a vtkImageData and reusing the vtkImageFFT filter. Instead, the vtkImageFFT filter should use the vtkTableFFT since that is more general. It also reduces dependencies of those wanting to do FFT of raw data to not require vtkImagingCore.

Cc: @utkarsh.ayachit (02ddfee8)