* 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 <[email protected]>

Co-authored-by: Tomasz Drwięga <[email protected]>

* do not refetch completion data instantly

* clippy

* Add some disclaimers about security decisions

* Be more explicit with warnings

* reward confirmation relayer

* Update modules/message-lane/src/instant_payments.rs

Co-authored-by: Hernando Castano <[email protected]>

* added some constants

* pallet_balances

* removed comment

* fix typo

Co-authored-by: Hernando Castano <[email protected]>

This reverts commit b774fa73.

This reverts commit f74dd660.

* Remove latest_*_nonce.

* cargo fmt --all

* Fix tests.

* cargo fmt --all

* Fix benchmarking.

* Update docs.

* `send_message` weight now depends on message size

* fix tests

* Update modules/message-lane/src/benchmarking.rs

Co-authored-by: Hernando Castano <[email protected]>

* Update modules/message-lane/src/benchmarking.rs

Co-authored-by: Hernando Castano <[email protected]>

Co-authored-by: Hernando Castano <[email protected]>