Get recent committed & rolled back blocks from the state service

[teor2345]

Motivation

Cancel Committed Transactions

• Add transaction IDs to the chain tip channel #2686
• Stop committing finalized queued blocks if there is an error  #2683
• Make chain tip updates and access more efficient #2695

We need to get a list of recently committed transaction IDs from the state service, so we can:

• Send mined transaction IDs to the download and verify task for cancellation #2711
• Send mined transaction IDs to mempool storage for removal #2713

Resets

• Add a ChainTipChange type to await chain tip changes #2715
• Reset ChainTipChanges on chain fork and network upgrade activation #2721

Resets are rare, so we can just clear the mempool when they happen.

Here are some different reset reasons:

Consensus rules

Network upgrades: stop mempool downloads and verifies, and clear storage and rejections

• ZIP-200: Test that mempool storage is cleared when a network upgrade activates #2374
• Cancel all mempool download and verify tasks when a network upgrade activates #2710

Chain rollbacks: stop rejecting transactions which spend rolled back inputs, by clearing our entire reject list

• Clear the mempool reject list when there is a chain rollback #2714

Zebra-specific

Initializing or cloning the receiver:

• we know we're not up to date

Skipped updates:

• we know we're lagging behind,
• we just received a large number of blocks,
• we had a chain fork change (rollback), or
• we might have skipped a network upgrade activation block, or a rollback or roll-forward over a network upgrade activation block.

Block Broadcasts

• Refactor BestTipHeight into a generic ChainTip sender and receiver  #2676
• Implement best tip block hashes for ChainTip receivers #2677

We need to get a list of recently committed block hashes from the state service, so we can:

• Broadcast AdvertiseBlock to peers when we commit a new block #2712

Out of Scope

Mempool activation and deactivation should be handled by SyncStatus:

• disable mempool: if the syncer starts syncing a lot of blocks, stop mempool downloads and verifies, and clear storage and rejections
• re-enable mempool: maybe we want a reset here too, depending on how we disable the mempool

[teor2345]

I moved nullifiers and outputs to #2631.