tower-abci: write integration tests for major cometbft releases

[erwanor]

The current process to test that support for major releases works is through manual testing: spin-up the correct version of cometbft and try to make it work with the key-value store example. Though we should keep some amount of manual testing as part of our quality assurance process, this much could be automated into the CI to make our development flow more robust to accidental regressions.

This ticket has growing priority, as we already support two major versions of CometBFT (with breaking changes to their socket wire protocol), and with #30, we will support one more.