[Refactor] Unifying the API for computing Lagrange Polynomials

[chancharles92]

Goal: have a unified and efficient implementation/API for computing the polynomial given n point-evaluation pairs.
E.g., the following two places are inlining different code for the same functionality.

jellyfish/primitives/src/reed_solomon_code/mod.rs

Lines 89 to 95 in 1a9db50

	// Lagrange interpolation:
	// Given a list of points (x_1, y_1) ... (x_n, y_n)
	// 1. Define l(x) = \prod (x - x_i)
	// 2. Calculate the barycentric weight w_i = \prod_{j \neq i} 1 / (x_i -
	// x_j)
	// 3. Calculate l_i(x) = w_i * l(x) / (x - x_i)
	// 4. Return f(x) = \sum_i y_i * l_i(x)

https://github.com/EspressoSystems/jellyfish/blob/kzg-multiproof-binyi/primitives/src/pcs/univariate_kzg/mod.rs#L621