Disconnect if a peer requests an EB body or EB closure that we don't have

[nfrisby]

We only offer EBs bodies/closures once we've acquired them. So if someone asks us for something we don't have, then we didn't offer it via LeiosNotify.

And we only select a CertRB (even as a tentative header) after we've received the EB body and closure, so we also didn't offer it via ChainSync.

Thus: they're requesting something we didn't offer, which is a (mini) protocol violation, and we should disconnect.