Move EIP712 dependency from AccountCore to Account

[Amxx]

As discussed during todays call, some account implementation may "vertically integrate" with the signer in a way were they raw sign the userOpHash (or similar).

Optional: we could remove the "default implementation" of _signableUserOpHash from AccountCore.

[ernestognw]

we could remove the "default implementation" of _signableUserOpHash from AccountCore.

I'm not sure since this is in the middle of validateUserOp, which makes it difficult to replace without overriding the whole validation

[ernestognw]

lfg! 🚀

[Amxx]

we could remove the "default implementation" of _signableUserOpHash from AccountCore.

I'm not sure since this is in the middle of validateUserOp, which makes it difficult to replace without overriding the whole validation

I did not mean to remove the function definition. I meant to keep the function definition, but without an implementation.

    function _signableUserOpHash(
        PackedUserOperation calldata userOp,
        bytes32 userOpHash
    ) internal view virtual returns (bytes32);