node: archive synchronization falls behind consensus over time

[Neotamandua]

Summary

When synchronizing from Genesis, the archive node falls behind in keeping up with the arrival of new blocks on the chain. For example, the chain::acceptor may already be accepting blocks at height 6200 while the archive is still finalizing & archiving events at height 5400.

Investigate why this is happening (on certain machines) and what the best solution is.