add all functions about complex Fourier transform and others

[sylviemonet]

Context: Yuan's leftover codes that may be useful but not in any branch now.

Description of the Change:

Benefits:

Possible Drawbacks:

Related GitHub Issues:

[codecov]

Codecov Report

Attention: Patch coverage is 76.19048% with 5 lines in your changes missing coverage. Please review.

Project coverage is 87.73%. Comparing base (c987f64) to head (da10f87).

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #401      +/-   ##
===========================================
- Coverage    87.77%   87.73%   -0.05%     
===========================================
  Files           81       81              
  Lines         6232     6252      +20     
===========================================
+ Hits          5470     5485      +15     
- Misses         762      767       +5     

Files	Coverage Δ
mrmustard/lab_dev/circuit_components_utils.py	100.00% <100.00%> (ø)
mrmustard/physics/triples.py	100.00% <100.00%> (ø)
mrmustard/physics/ansatze.py	92.59% <16.66%> (-2.49%)	⬇️

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[ziofil]

Falling too far behind. Will move to a new PR.