improve startup process to avoid missing blocks

[MicaiahReid]

Currently, when chainhook starts up, all blocks between the ingested archive's last block and chain tip are missing. We need to fetch these blocks and add them to the local chain state so there aren't gaps.

[MicaiahReid]

So a stacks node will stop progressing until Chainhook is back up, so if Chainhook goes down there shouldn't be any gaps in the blocks.

From my investigations, I think these gaps are happening during a reorg where:

• chainhook crashes (maybe, it could just be untimely restarts)
• chainhook restarts and receives blocks that were missed
• those blocks contain some re-org blocks
• Chainhook doesn't have any blocks queued up in its fork indexer, so it can't correctly determine which is canonical
• So Chainhook fails to process incoming blocks, but the stacks node is successfully able to emit the blocks, so now we've lost our store of what happened while chainhook was down

All that to say, #487 is a more appropriate issue to resolve the problems we're seeing. Closing this ticket in favor of that one.