The current way a proof is registerd is to add a node, which is only
possible if we already met a node advertising this proof in a valid
delegation.
This adds a way to register a proof into the PeerManager without a delegation, for proofs received via the inventory network messages.
delegation, for proofs received via the inventory network messages.
Depends on D9468It also adds a `getProof` method for the network layer to be able to find out if we already know of a proof when receiving an inventory, for allowing the PeerManagerand to relay that proof to take ownership of proofspeers if we have it.
The next step is to add a container to be able to register orphans proofs.