Bubble up errors better #816
Description
Background
There are situations where we return a 504 error to the user without bubbling up more information about why.
For example, below shows a case where the block failed to pass hash verification due to a bug in Helia (even though the block was successfully downloaded), but the user isn't informed about what went wrong.
While this case is due to a bug in Helia, it's a great example of the kind of error we'd want to surface to the user: when hash verification fails!