* Move justification module to header-chain primitives crate
* Get justification module compiling in new location
* Get justification module tests compiling
* Use justification code from `header-chain` crate
Mostly compiles, having issues with std/test feature flags across crates.
* Move some code around
* Move justification tests to integration testing crate
* Add `test-utils` crate
* Remove tests and test-helper module from justification code
* Use `test-utils` in Substrate bridge pallet tests
* Remove `sp-keyring` related code from `pallet-substrate-bridge`
* Remove `helpers` module from `pallet-substrate-bridge`
* Add some documentation
* Add more documentation
* Fix typo
Co-authored-by: Tomasz Drwięga <tomusdrw@users.noreply.github.com>
Co-authored-by: Tomasz Drwięga <tomusdrw@users.noreply.github.com>
Hernando Castano