Companion for Bridges V2 - relay client part (#2988)

* Dienerized to polkadot-sdk@bko-bridges-backports-and-nits

* cargo update -p sp-io

* Change substrate-relay version

* Update polkadot-sdk master ref

* Setup latest master with merged: paritytech/polkadot-sdk#4494

* Change relayer version for release

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Co-authored-by: Svyatoslav Nikolsky <svyatonik@gmail.com>