bezier(pt1: Vec2 , pt2: Vec2 , pt3: Vec2 , pt4: Vec2 ): Vec2

A second order function returning an evaluator for the given 2D quadratic Bezier curve

parampt1- First point

parampt2- First control point

parampt3- Second control point

parampt4- Second point

returnsA function which gives the value on the 2D quadratic Bezier curve at t