Function artha::matrix::mse_diff

pub fn mse_diff<T>(
    one: &Matrix<T>, 
    another: &Matrix<T>
) -> Result<f64, Box<dyn Error>> where
    T: Sub + Clone,
    f64: From<<T as Sub>::Output>, 

Finds the mean squared difference of the matrix with another matrix

Note: Since calculating MSE of each value in the matrix requires it to be converted to floating point as powi is not a trait, this function returns f64 Matrices.