Add spiral shape

[stefmolin]

Fixes #177

Describe your changes

Added Spiral target shape

Checklist

• Test cases have been modified/added to cover any code changes.
• Docstrings have been modified/created for any code changes.
• All linting and formatting checks pass (see the contributing guidelines for more information).

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.53%. Comparing base (c82a381) to head (9e38f67).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #264      +/-   ##
==========================================
+ Coverage   98.52%   98.53%   +0.01%     
==========================================
  Files          58       59       +1     
  Lines        1898     1915      +17     
  Branches      112      112              
==========================================
+ Hits         1870     1887      +17     
  Misses         25       25              
  Partials        3        3              

Files with missing lines	Coverage Δ
src/data_morph/shapes/factory.py	100.00% <ø> (ø)
src/data_morph/shapes/points/__init__.py	100.00% <100.00%> (ø)
src/data_morph/shapes/points/spiral.py	100.00% <100.00%> (ø)
tests/shapes/test_points.py	100.00% <100.00%> (ø)