Add TeleporterMessenger Go binding

[cam-schultz]

Context and scope
We should add Go bindings for the TeleporterMessenger ABI. For example, the awm-relayer implements this separately, but that is decoupled from the contract itself. By hosting those bindings in this repo, we could tightly couple them by adding scripts or CI jobs to autogenerate the binding or verify that the checked in binding matches the contract.