Change Default ProofSpecs for SDK SMT change

[AdityaSripal]

When the SDK SMT change comes in, we'll have to change our default proofspecs to reflect the new proofspecs for SDK chains.

This would involve changing the following line:
https://github.com/cosmos/ibc-go/blob/main/modules/core/23-commitment/types/merkle.go#L17

to SMTSpec, TendermintSpec

and then testing the combined SDK/IBC changes

[crodriguezvega]

@AdityaSripal I think at the moment hermes is using these default proof specs in the MsgCreateClient that creates the light client. With the upcoming SMTSpec, will the hermes relayer need to implement and use this new spec when creating the light client for a chain that supports SMTSpec and TendermintSpec?

[AdityaSripal]

We need to implement a query that is available on all chains so that relayers can simply query the chain to determine what proof specs to use for the client. cc: @colin-axner

[robert-zaremba]

Why there is a default proof spec? Shoudn't that be implied by the SDK / IBC config? Default sounds dangerous here - what if someone will forget to configure?

[crodriguezvega]

Thanks for the comment, @robert-zaremba. Yes, I guess you're right and it would be more flexible if ibc-go could dynamically figure out what proof specs to use. @AdityaSripal, any idea if this could be feasible?

[damiannolan]

can we close this? IIRC sdk do not plan to migrate away from iavl anytime soon?