* Delete deploy contract tool. Move mock to its own package as testonly with some helper functions
* gofmt contracts/deposit/mock/mock.go
* move stategen mock.go to its on testonly pkg
* move password_reader_mock.go to mock testonly package
* move mock keymanager to its own testonly package
* move attestations mock
* move voluntaryexits mock
* Move slashings mock to mock pkg
* move the slasher mock
Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>
* Move domain function and all signing root functions from beacon-chain/core/helpers to beacon-chain/core
* @terencechain suggestion to put these methods under core/signing
