feat: allow delaying transactions in ResponsePrepareProposal

[lklimek]

Issue being fixed or feature implemented

ABCI App must check if the size of transactions does not exceed max limit.
If it does, it should reject the transaction. Unfortunately, only abci.TxRecord_REMOVED, action is available that removed the tx from mempool.

This should not be a problem in a system where there are many validators, as the tx should be added to next block by another proposer (which didn't remove it from mempool yet). However, for a relatively small validator set, this can lead to dropped transactions in some edge cases.

What was done?

Introduced abci.TxRecord_DELAYED, which should remove the transaction from proposal/block, while still leaving it in the mempool.

Refactored kvstore and e2e example apps to better support testing of transactions.

Refactored logs to only include hash of tx, not full tx

How Has This Been Tested?

Added e2e test that tests this feature.

Breaking Changes

None - only new action added in ResponsePrepareProposal, but the system should work just fine with apps that don't support this action (as it's in response).

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have made corresponding changes to the documentation

For repository code-owners and collaborators only

• I have assigned this pull request to a milestone

[shumkov]

Nice! 👍

[markin-io]

utACK