feat(poly): univariate poly eval

[cyphersnake]

Univariate polynomial and evaluation
This is straightforward.
A uni-variate polynomial is represented by its coefficients. Can be simply defined as a vector.

Definition: P: Vec<F>
Evaluation fn eval(P, x)

struct UnivariatePoly(Vec<F>)

impl UnivariatePoly {
    pub fn eval(self, x: F) -> F { todo!() }
}