Implement ethereum explicitly related currency swap logic to make Native-to-EVM Bridge transactions visible via Ethereum RPC

[dmitrylavrenov]

Design thoughts

• A new pallet that contains ethereum explicitly related currency swap logic. We need to make Native-to-EVM Bridge transactions visible via Ethereum RPC
• Use https://github.com/humanode-network/frontier/blob/174c0227af00dbc26485c1eac68738e1d01980e8/frame/ethereum/src/lib.rs#L964 to make the transaction visible at ethereum side
• Avoid using Currency in favour of fungible related traits like Inspect and Mutate

Tasks

• pallet implementation
• precompile implementation
• runtime integration
• runtime unit tests
• unit tests for native to evm swap
• unit tests for evm to native swap
• e2e tests for swap in both directions

P.S: do benchmarks at separate PR

PoC of visibility

transaction itself

transaction execution in explorer on Substrate RPC side

transaction execution in explorer on Ethereum RPC side

Very tiny ethereum explorer is used to verify visibility via Ethereum RPC

[MOZGIII]

This looks good!

If we add the E2E tests to verify that the solution works overall, and unit tests with mock runtime (as we usually do) to test the niche cases (zero transfer, etc) and for tight regression control - I think we ship it pretty much right away

[MOZGIII]

Thinking about this, we should explicitly test, among other things, that the pot doesn't pay the fee for any tx with this flow.

[dmitrylavrenov]

Thinking about this, we should explicitly test, among other things, that the pot doesn't pay the fee for any tx with this flow.

Tested manually that pot doesn't pay the fee - confirmed. Additionally will implement some unit tests and add this check to e2e test.