feat: add fft/base/fftpack/decompose

[gunjjoshi]

Resolves None.

Description

What is the purpose of this pull request?

This pull request:

• adds fft/base/fftpack/decompose, which is a part of fftpack.
• is an extension of feat: add initial implementation of fft/base/fftpack #4121.

This package decomposes a number (sequence length in the context of FFT) into its factors, so that we can process the smaller sequences independently, rather than processing the whole sequence length at once, during the fast Fourier transform.

Related Issues

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None.

Questions

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No.

Other

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Test coverage report:

Checklist

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• Read, understood, and followed the contributing guidelines.

AI Assistance

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Used AI to suggest test cases that can be implemented.

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Coverage Report

Package	Statements	Branches	Functions	Lines
fft/base/fftpack/decompose	$\color{green}250/250$ $\color{green}+0.00%$	$\color{green}17/17$ $\color{green}+0.00%$	$\color{green}1/1$ $\color{green}+0.00%$	$\color{green}250/250$ $\color{green}+0.00%$

The above coverage report was generated for the changes in this PR.