check the da cache and the attester cache in responding to RPC requests

[realbigsean]

Issue Addressed

Resolves https://github.com/sigp/lighthouse/issues/5093

Proposed Changes

• Check the DA cache then the attester cache in responding to block by range requests
• ~~This does not currently check if a block exists in the DA cache's overflow to disk, I'm sort of thinking that's overkill. But can add it in.~~ I decided to use the processing_cache because this includes payloads we haven't verified. This is technically correct according to the spec

[realbigsean]

Ok feedback so far has been addressed

[paulhauner]

@Mergifyio queue

[mergify[bot]]

queue

✅ The pull request has been merged automatically

The pull request has been merged automatically at f21472991dbbc9e6e18310a01fc2c4d9ce7c7348