Modified align2d()

[SunPeike]

Fixed bugs in align2d():

1. fixed the **m factor in modes_A(t_reference + δt) * np.exp(1j * m * δϕ) * float(δΨ_factor)**m (Aside: float() since numpy cannot raise int to negative power)
2. introduced max_nfev, ftol as arguments
3. defined _cost2dls, a residual vector for least_squares, while keeping the initial scalar cost for the brute force stage
4. fixed the interval for n_brute_force_δt
5. deleted normalization, as this would only scale the brute force cost by a positive factor
6. introduced the support of Levenberg-Marquardt in the least_squares stage, together with the original Trust Region Reflective method. Set lm as default due to better performance.

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📚 Documentation preview 📚: https://sxs--168.org.readthedocs.build/en/168/

[codecov-commenter]

Codecov Report

❌ Patch coverage is 65.62500% with 11 lines in your changes missing coverage. Please review.
✅ Project coverage is 43.99%. Comparing base (a24528c) to head (6516be4).
⚠️ Report is 57 commits behind head on main.

Files with missing lines	Patch %	Lines
sxs/waveforms/alignment.py	65.62%	8 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #168      +/-   ##
==========================================
- Coverage   44.15%   43.99%   -0.16%     
==========================================
  Files          83       82       -1     
  Lines        6192     6207      +15     
  Branches     1008     1013       +5     
==========================================
- Hits         2734     2731       -3     
- Misses       3207     3222      +15     
- Partials      251      254       +3     

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