Add Fourier analysis tool to Statistics submenu.
Use FOURIER() formula to do all the work here.

Change-Id: Ifdaa79d8ee367f1c1f5054248e01853ffe4c6823
Reviewed-on: https://gerrit.libreoffice.org/69472
Tested-by: Jenkins
Reviewed-by: Dennis Francis <dennis.francis@collabora.com>