Simplify config for initializing multisig through infra

we have support in our npm package for initializing a multisig + storing the info needing to use it in a subsequent PR, but this makes the infra integration harder.

Ideally we should just be able to describe an "unitialized account" in our accounts spec for our contract deployment, and that can be used and converted into an initialzied multisig account from our infra CI