Port safe commits from master to polkadot-staging (#2761)

* introduce bp_messages::ChainWithMessages (#2171)

* Move Chain::ID from relay-level Chain to primitives-level Chain (#2181)

* move Chain::ID from relay-level Chain to primitives-level Chain

* removed chain IDs from bp-runtime

* add missing file header

* Some code grooming (#2276)

* some code grooming: enable warn(missing_docs) for all piblic crates + added missing documentation + removed obsolete clippy/deny workarounds

* removed strange allow + added comment related to other allow

* removed incorrect_clone_impl_on_copy_type which is unknown to CI clippy