Submit exchange transactions to PoA node (#229)

* submit Eth exchange transactions

* submit ethereum in docker-compose

* submit Eth exchange transactions

* fix duplicate message

* fix relay script

* lost file

* cargo fmt --all

* cargo +nightly clippy

* Show sccache

* remove test-helpers remains

* what's going on with jsonrpsee + Cargo.lock?

* relay-eth-submit-exchange-tx -> poa-exchange-tx-generator

* Update relays/ethereum/src/main.rs

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

* configuring exchange-gen loop using env variables

* fixed signer account from dev chain to Arthur

* improve debug prints

* parse nonce from relay output

* --eth-nonce=

* fix compilation

* cargo fmt --all

* fix typo

* duplicate relay output to tty

* allow using from bash scripts tests

* fix: U256::parse() expects hex string :/

* cargo fmt --all

* BRIDGE_HASH: ${BRIDGE_HASH:-master}

* script comment

* generate exchange PoA transactions by Bertha

* Bertha address

Co-authored-by: Denis S. Soldatov aka General-Beck <[email protected]>
Co-authored-by: Tomasz Drwięga <[email protected]>