[Needle][algorithm] Enabled insertion-removal cycles in the algorithm

[th-skam]

Issues

Close #31
Close #39
Close #28

[th-skam]

Coupling points are removed based on their position relative to the needle tip. Specifically, for each coupling point, compute the dot product between:

• the vector $\overrightarrow p$ from the needle tip to the coupling point, and
• the unit vector $\overrightarrow n$, which points in the direction of the last needle segment and defines the plane perpendicular to that segment.

If the dot product $\overrightarrow p \dot{} \overrightarrow n$ is positive, the coupling point is in front of the needle tip and should be removed.

This check assumes that the needle will not diverge dramatically from each original orientation.