Add create2 factory router

[lmcorbalan]

TODO

• Deployment script
• Interchain Message send script example
• Write README How to use section

[nambrot]

One thing we probably didn't specify is that ideally this router includes remote router overrides like callRemoteWithOverrides of InterchainAccountRouter, to allow callers to reuse the existing router address on an existing chain, but not require the owner of the router to populate the routers mapping (since folks can deploy hyperlane themselves).

[lmcorbalan]

since folks can deploy hyperlane themselves

So that's what the Overrides is for!
Taking into account the other comment, we would need to offer to override the hook here as well and call directly to mailbox.dispatch instead _Router_dispatch which uses _mustHaveRemoteRouter.

[nambrot]

I would be important to offer to override the hook itself as well (if the caller wants to pay a different relayer, or use a different ISM that needs a post dispatch hook (like rollup bridges)

[lmcorbalan]

if we offer to override the hook here then we should do the same for deployContract, right? and I won't be able to user re Router._Router_quoteDispatch because it uses _mustHaveRemoteRouter(_destinationDomain);

Something like:

function quoteDispatch(
    uint32 _destinationDomain,
    bytes32 _router,
    bytes memory _messageBody,
    bytes memory _hookMetadata,
    address _hook
) internal view returns (uint256) {
    return
        mailbox.quoteDispatch(
            _destinationDomain,
            _router,
            _messageBody,
            _hookMetadata,
            IPostDispatchHook(_hook)
        );
}

[nambrot]

Indeed

[lmcorbalan]

Hey @nambrot I made the requested changes, let me know what you think please!!

[nambrot]

Sorry for the delay here, lgtm to merge!