Add geometric cost functions

[Flova]

The original bio ik features cost functions to keep a given link on a line, plane etc.. Are they also planned for pick ik?

[sea-bass]

The goal would be to establish (and then exceed) parity with the bio_ik features, absolutely.

There's no immediate short-term plan to work on this, so we'd welcome any open-source contributions to make new cost functions in pick_ik like these, though!

[Flova]

Okay, I might port them if I have some spare time!

[sea-bass]

@Robotawi is also going to look into making more cost functions soon as well, I believe!