Integrate new FFT iterative algorithms and tidy-up the FFT API

[xqft]

Integrate new FFT algorithms and tidy-up the FFT API

Description

This is a follow up of #127. The changes remove the previous recursive FFT algorithm and integrates the new, faster ones. Also adds new methods for twiddle/roots of unity generation and tidies-up the API in general.

This is part of our efforts for #116.

Type of change

Please delete options that are not relevant.

• New feature
• Optimization

Checklist

• Unit tests added
• This change requires new documentation.
  • Documentation has been added/updated.

[codecov-commenter]

Codecov Report

Merging #167 (e8e006d) into main (95fe19f) will increase coverage by 0.24%.
The diff coverage is 98.98%.

@@            Coverage Diff             @@
##             main     #167      +/-   ##
==========================================
+ Coverage   96.16%   96.40%   +0.24%     
==========================================
  Files          52       51       -1     
  Lines        6334     6369      +35     
==========================================
+ Hits         6091     6140      +49     
+ Misses        243      229      -14     

Impacted Files	Coverage Δ
math/src/fft/fft_iterative.rs	100.00% <ø> (ø)
math/src/field/traits.rs	93.15% <95.65%> (+4.91%)	⬆️
math/src/fft/abstractions.rs	100.00% <100.00%> (ø)
math/src/fft/bit_reversing.rs	100.00% <100.00%> (ø)
math/src/polynomial.rs	98.42% <100.00%> (+0.38%)	⬆️
math/src/field/test_fields/u64_test_field.rs	81.57% <0.00%> (+7.89%)	⬆️
math/src/fft/helpers.rs	100.00% <0.00%> (+37.50%)	⬆️

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[IAvecilla]

Just some minor details but everything looks good

[ilitteri]

LGTM