Consider if blockstore interface needs optimizations

[justindotpub]

In some of my testing it has appeared that our current simple approach to getting blocks from the store may be a bottleneck. If this is indeed true, we may need to consider adding other methods to our blockstore interface, like GetMany, or some kind of traversal methods.

ETA: 2023-10-31

[justindotpub]

I've added this to the Batch milestone, only because of my initial observation of what seems to be a bottleneck. Confirm and pull out of the batch milestone if not deemed a large enough impact.

[justindotpub]

My experience indicates this will also relate to #102 with needing to bump up timeouts in tests when you have too many blocks.

[justindotpub]

Update test timeouts to fail tests in such cases, so we don't silently miss these.