Claim funds on Substrate chain by providing proof of funds locking on PoA chain (#91)

* ethereum exchange module

* continue

* continue

* added tests for exchange module

* moved

* remove println

* move again

* fixes

* removed redundant deps

* cargo fmt

* fund_locks_transaction_decode_works

* cargo fmt --all

* fix error processing

* added some tracing to bridge modules

* more tests

* more tests

* cargo fmt --all

* kovan.rs -> exchange.rs

* Update bin/node/runtime/src/exchange.rs

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

* added assumption doc

* Airdrop -> DepositInto

* AsIs -> Identity

* OnTransactionSubmitted

* Transfers::Key = Id

* typo

* Update bin/node/runtime/src/exchange.rs

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

* block+tx+proof -> proof { block, tx, proof }

* cargo fmt --all

* docs

* check <-> verify

* parse hex

* extracted exchange primitives to separate crate

* added docs to runtime::exchange module

* Update bin/node/runtime/src/exchange.rs

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

* typo

* Update modules/currency-exchange/Cargo.toml

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

* add docs to currency-exchange module

* change tests names

* cargo fmt --all

* Update bin/node/runtime/src/exchange.rs

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

* Update bin/node/runtime/src/exchange.rs

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

* Update bin/node/runtime/src/exchange.rs

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

* Update bin/node/runtime/src/exchange.rs

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

* Update bin/node/runtime/src/exchange.rs

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

* fixed verify_transaction_finalized for siblings of finalized blocks

* cargo fmt --all

* added double spend note

* cargo fmt --all

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