Adding Position class and function getClosestEdgePosition

New class!
Position
An edge position along an edge, has pct, offset, and edge, and thetaOffset (for rotation), but is also a valid Transform.
refresh() -> sets it from the current position of the edge
getEdgePoint -> get the point *on* the edge (ignore the offset)
drawCircle -> useful drawing function, shows both the point, it's rotation, and the edge point it's at.

bot.getClosestEdgePosition(target) -> return the edge position closest to this point