Single lookups should consider processed/processing blocks/blobs

[realbigsean]

Description

Observing on devnet 8 that we are doing too many single block lookups, looking up blocks/blobs that we've already processed. This is because of a combination of the delayed lookup logic (which waits for a period of time to see whether we get all block components over gossip before triggering a request), and the fact that we're only checking the DataAvailabilityChecker for missing components, not considering currently processing or previously processed and imported blocks/blobs.

We are frequently:

1. queuing a delayed lookup request
2. then receiving all block components on gossip, meaning the delayed lookup request is no longer needed
3. importing the block
4. then dequeuing the delayed lookup, being unaware the blocks been fully imported

We should additionally consider blocks/blobs that we are processing but have not yet hit the DataAvailabilityChecker. Perhaps this be done with our gossip "seen" caches?

[realbigsean]

resolved in #4732