Port Espresso/hyperplonk's `virtualpolynomial`, `multilinearpolynomial`
and `sum_check` utils from
https://github.com/EspressoSystems/hyperplonk/tree/main
Each file contains the reference to the original file.

Porting it into a subdirectory `src/utils/espresso`, to have it
self-contained. In future iterations we might replace part of it but we
can keep focusing on the folding schemes part for now.