SpiralGroundCurve: initial implementation.

[agalbachicar]

🎉 New feature

Part of #265

Summary

• Partial implementation of the SpiralGroundCurve.
• Test coverage for the entire class when the curve is built with normalized parameters.

Some TODOS in the implementation were left in favor of submitting a partial implementation that is properly covered with unit tests. It is in favor of a more digestible and focused review of the math involved here.

Test it

Via unit tests.

Checklist

• [x] Signed all commits for DCO
• [x] Added tests
• [ ] Added example and/or tutorial
• [ ] Updated documentation (as needed)
• [ ] Updated migration guide (as needed)
• [ ] Consider updating Python bindings (if it affects the public API)

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[agalbachicar]

Adding you all as reviewers, but probably not all are required. Given that @francocipollone is OoO, I will need to rely on you @stonier and @liangfok.

[agalbachicar]

Declining in favor of a new implementation.