feat: add `target-chain-height` to `commit-block`

[obycode]

Description

This allows us to check if the target block is anywhere in the past, not just the last block. That means if the block commit misses its target block, but lands in a different block that is still in the same fork as the target block, then the block commit can be successful.

Checklist

• [ ] Test coverage for new or modified code paths
• [ ] Changelog is updated
• [ ] Required documentation changes (e.g., docs/rpc/openapi.yaml and rpc-endpoints.md for v2 endpoints, event-dispatcher.md for new events)
• [ ] New integration test(s) added to bitcoin-tests.yml

[obycode]

This PR still needs tests added.

[obycode]

This has been integrated into #248.