Function mel::enumerate_mel_scaling_matrix_base

pub fn enumerate_mel_scaling_matrix_base<WindowIter>(
    min_hertz: f64, 
    max_hertz: f64, 
    input_size: usize, 
    output_size: usize, 
    mel_from_hertz: fn(_: f64) -> f64, 
    hertz_from_mel: fn(_: f64) -> f64, 
    window_function: fn(_: usize) -> WindowIter
) -> MelScalingMatrixEnumerator<WindowIter> where
    WindowIter: Iterator<Item = f64>, 

(or many vectors at once in form of a matrix) to transform that vector into mel space. efficiently rows are mel cols are freq TODO get frequency index pair for nth mel TODO enumerate scaling vector TODO which dimension first