chore: warp route deploys a defaultIsm

[ltyu]

Problem

Currently, the cli deploys a defaultIsm when a user does not deploy a trustedRelayerIsm. This differs from infra, which sets the ISM to address(0). Although they achieve the same-ish things (both defaultIsm with no modules and address(0) will use mailbox default ism), it is inconsistent and also a waste of gas.

Solution

Consider deploying a warp route with ISM set to address(0), if trusted relayer is not used.