add distanceFromSegment function to amathutils_lib

New feature implementation

Implemented feature

Added function to calculate distance between a point and a line segment.
This function is meant to be used in vector_map_converter package, but was added to amathutils_lib for others to use it.

Implementation description

The code was implemented by referring to following website. http://geomalgorithms.com/a02-_lines.html

Note to reviewer: If there is a proper way to credit the code, please let me know

Test Procedure

Converting from Lanelet2

1. colcon build
2. colcon test
3. confirm that no error appears during the test

Related Merge Request

utilities!2 (closed)