tendermint proto imports are not consistent between cosmos-sdk and ibc-rs revisions

[mzabaluev]

The upstream proto revisions as currently pulled to build ibc-proto-rs are not consistent as per the revisions of tendermint files they expect to import:

• cosmos/cosmos-sdk@2e9e5d6 uses v0.37
• cosmos/ibc-go@57fcdb9 uses v0.38
• cosmos/interchain-security@ea545b4 uses v0.37

However, by the way the build process is set up in sync-protobuf.sh, all of these inputs to proto-compiler actually end up including the tendermint/* protobuf files found in the cosmos-sdk buf export (the proto-include directory).
Which means our ibc:: generated types for this set of upstream revisions do not necessarily interoperate with the Go types generated in ibc-go as per the targeted commit.

The proper way out of this mess is to convert the upstreams to produce buf modules and reuse buf.build/cometbft/cometbft as a common dependency. Then the build process in ibc-proto-rs could consume the buf modules to generate Rust bindings for them.

Meanwhile, it's possible to juggle the src/*_COMMIT files in ibc-proto-rs to arrive at a combination of proto upstreams that happens to use the same revision of the tendermint protos, and then do the extern_path trick on that. But it's a high-quality balancing act that needs developer's time and care. Which is precisely what buf is meant to get rid of.

Originally posted by @mzabaluev in cosmos/ibc-rs#1073 (comment)

[mzabaluev]

From a discussion on Slack, the best quick course of action is to bring all dependencies to Tendermint/CometBFT 0.38.
But in case of ICS, it is blocked on cosmos/interchain-security#1246.

[mzabaluev]

5bb2b45 (in #190) brings the cosmos-sdk checkout up to v0.50.4. In terms of the tendermint version, this gets the includes up to 0.38.

We're in luck with interchain-security: it uses tendermint.crypto.PublicKey, tendermint.abci.Validator, and tendermint.abci.ValidatorUpdate, the definitions of which have not changed since 0.34. So we are able to hold up this house of cards for now.