Feat: create USegment, which doesn't matter their parameters

[carlos-adir]

This PR adds a new class USegment which is equivalent to the Segment but doesn't have parameters.

The main motivation is to allow compare two Segment with different parameters.
Example, suppose:

$$p(t) = (1 - t, 2 + 3 t)$$

$$q(t) = (1 - t^3, 2 + 3t^3)$$

We see that $p(t) != q(t)$, but in fact both leads to the same set of points.

With the addition of this class, comparing two JordanCurve instances becomes easier

[codecov]

Codecov Report

❌ Patch coverage is 99.50739% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 97.87%. Comparing base (30963dc) to head (d6507d1).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
src/shapepy/geometry/unparam.py	97.87%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #57      +/-   ##
==========================================
- Coverage   98.12%   97.87%   -0.26%     
==========================================
  Files          28       29       +1     
  Lines        2402     2444      +42     
==========================================
+ Hits         2357     2392      +35     
- Misses         45       52       +7     

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