IBC error handling / dispatching

[maurolacy]

@maurolacy cloned issue babylonchain/babylon-contract#100 on 2024-05-15:

Currently the IBC handler is in babylon-contract. BTC staking messages are dispatched to the btc-staking contract for processing, by returning an execution message from the IBC handler destined to the staking contract.

What happens if that execution message fails in the staking contract, for whatever reason? My understanding is, that the error will be catch as part of return handler processing, and should be propagated the to calling IBC party. That is, the zoneconcierge module on the Provider.

But perhaps this is not the case. Or, our current IBC handler needs to be modified / adapted for this to be the case. Perhaps the error is just logged on the Consumer side, perhaps it's being silently ignored, etc.

Creating this issue to understand and document this process. And modify the IBC handler if needed.

Let's research / investigate how IBC error handling works, so that we know / understand how an error on a Consumer side contract is dispatched to the Provider, and confirm it's not being silently swallowed in the process.