fix(signer-ledger): use SIGN_ETH_EIP_712 instruction

[Karrq]

Motivation

Signing EIP712 messages thru alloy_network::TxSigner's sign_transaction results in the usage of SIGN instruction which does not support EIP712 messages.

Solution

Detect if the incoming tx is indeed a EIP712 transaction and dispatch to the appropriate method

PR Checklist

• Added Tests
• Added Documentation
• Breaking changes

[mattsse]

not that familiar with this api

wdyt @DaniPopes

[DaniPopes]

There's no such thing as a EIP-712 transaction, nor does any of the existing transaction ever return EIP-712-encoded data, so I don't know what this is trying to accomplish.

[DaniPopes]

Nevermind, apparently there is #142
Please add a comment for this
cc @prestwich

[Karrq]

This allows foundry-zksync to sign transactions using ledger, since we make use of sign_transaction to sign the encoded eip712 transacion.