Adding an MKL adapter in FFT module.

Fix missing template argument bug in FFT header for mkl adapter. Add adapter inplementations for mkl, kfr and ffts FFT libraries. oneAPI mkl is now free both dor Winlows and Linux and gives performance similar to fftw for Intel CPU.kfr FFT gives performanse similar to fftw. It requires either GPL or comercial license. FFTS gives good performans. There is no developers activity for last three years. Another drawback is thet FFTS has not completed real to complex and 2d transformation for double precission. For 1d real to complex and backward transformation I have to convert real array to complex with Im = 0.