More helpful `OffsetOutOfRange` error

[crepererum]

OffsetOutOfRange may happen on two sides:

1. The offset that we are trying to read was deleted (either via the API or via the retention policy)
2. The offset does not exist yet (or is gone for another reason, e.g. because a topic was re-created).

Both cases are reported using the very same error code, but the FETCH response should have enough information (log start, high watermark) to determine the difference.