Audit baseapp v0.47...v0.50

[alexanderbez]

[facundomedica]

Changes:

Important:

• Return error during ExtendVote and VerifyVoteExtension if the request height is earlier than VoteExtensionsEnableHeight (see comments in this pr).
• Added hash to context header info in ExtendVote
• VoteExtensions are disabled by default unless consensusParams.Abci != nil AND if cp.Abci.VoteExtensionsEnableHeight > 0 AND req.Height >= cp.Abci.VoteExtensionsEnableHeight.

Other:

• Added instructions on how to enable vote extensions in Upgrading.md
• Increase test coverage
• Fix some tests to conform to the expected behavior (txs not changing between ProcessProposal and FinalizeBlock)
• Also missing docs on CometBFT: https://github.com/cometbft/cometbft/issues/1036

Notes/Qs:

• SetStreamingService was removed at https://github.com/cosmos/cosmos-sdk/pull/14207 should it get added to changelog?
• TestABCI_MultiListener_StateChanges has some commented lines, not sure if solvable right now tho

[alexanderbez]

Closing this soon as we've addressed all major concerns. Would appreciate perhaps a third look (@julienrbrt?) since this is such a high impact area of the code.

[julienrbrt]

Sure, I can give it a look later this week!

[julienrbrt]

I have not found anything problematic. Just some nits here and there. Once there is a testnet up we should verify state sync works as I have not tried it.