* add new helpers
* make zerohash public
* remove unused method
* add more tests
* cleanup
* add in new tests
* fix all tests
* Apply suggestions from code review
Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>
Co-authored-by: Raul Jordan <raul@prysmaticlabs.com>
