Can not generate tendermint-proto from source with buf dependencies

[mzabaluev]

Description

Originally reported as cometbft/cometbft#565

tendermint-proto-compiler needs to be able to process buf dependencies in the buf.lock file in order to fetch third-party
protobuf modules used by CometBFT proto module source in releases starting from 0.37.0.
For #1193 I have scrounged by generating off the v0.37.0-alpha.1 release and checking that the proto source has not changed between then and the eventual 0.37.x releases, but to adapt to any future changes we need to adapt to the buf way of managing protobuf dependencies.

Definition of "done"

The tool that's used to generate code for tendermint-proto (either t-p-compiler or, if you feel ambitious, switch completely to buf.build) can deal with the buf dependencies in CometBFT releases since v0.37.0.

[tony-iqlusion]

We're dealing with a similar issue on cosmos-rust: cosmos/cosmos-rust#318

So far we modified our proto-build to shell out to buf, however protoc-gen-prost looks promising: https://github.com/neoeinstein/protoc-gen-prost

[mzabaluev]

I'm implementing it as a shell-out as well, to have a tendermint-proto-compiler that can work with older v0.34.x checkouts as well as v0.37.x and later revisions in the CometBFT repository.

We will switch to full-on buf for generation and transition to using versioned cometbft protos as a source at a later time.