Add ink! E2E test: Use ink! contract in hardhat script, sign via metamask.

[cmichi]

We believe that it's already possible to have Metamask interact with ink! contracts that have the Solidity ABI encoding enabled. Enabling this can be done via

#[ink::contract(abi = "all")] or #[ink::contract(abi = "sol")]

I'm copy/pasting from a discussion in Element.

Peter:

On the calling and interaction side, it should work already (from a raw call data perspective). Local testing just requires an eth-rpc to be running (example: polkadot-sdk/target/release/eth-rpc --dev --node-rpc-url ws://127.0.0.1:944).

From a metadata perspective, David could answer best. But IIRC, I wonder if we could add an ink! contract to a hardhat script and test it like that (signing via metamask)

David:

The metadata (in this case the .abi file) should work fine too for any contract that compiles successfully with abi = "<sol|all>"