feat: FFT and IFFT based on domain

[0xJepsen]

Feature

Allows us to convert between the two bases via evaluation at roots of unity / inverses.

[0xJepsen]

@Autoparallel did the Reed Solomon Encoding PR closed this?

[kevaundray]

Looking at the PR, I don't think it closes it -- it does a DFT but it is not doing it via the FFT, its doing it via polynomial evaluation

[Autoparallel]

Marking as a good first issue as DFT is already done, FFT is not much more than a case for powers of two that can be divide-and-conquered!

[mahmudsudo]

can i take on this FFT ?

[Autoparallel]

Absolutely