Adds spiral geometry parsing capabilities

[francocipollone]

🎉 New feature

Related to #260

Summary

From OpenDRIVE Format Specification 1.5:

This record describes a spiral as part of the road’s reference line. For this type of spiral, the curvature
change between start and end of the element is linear.

In order to provide consistency between spiral evaluations of various implementations, users are
highly recommended to use identical algorithms, or, at least, algorithms with reasonable accuracy
within the applicable range (i.e. curvature, length of spiral etc.).

The theory of clothoids is described (for example) at
http://en.wikipedia.org/wiki/Euler_spiral
A library for computing clothoids can be downloaded at
http://www.opendrive.org/downloads/spiral.zip

Test it!

After building and sourcing.

xodr_query src/maliput_malidrive/resources/SpiralRoad.xodr GetGeometries 1

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)